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Nemo Disco Endless Promise 15 Sleeping Bag Review

Adam Sanders
Paul Sozio bio photo
ByMultiple Authors
Mar 09, 2026
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Our Take:
4.3/5
Editors' Pick
Certified

The Nemo Disco Endless Promise 15 ($300) is a comfortable, feature-rich sleeping bag that prioritizes roominess and temperature control. Its hourglass shape, excellent ventilation, and thoughtful details make it one of the most luxe-feeling backpacking bags we’ve used, especially if you’re a side sleeper. It’s heavy and bulky compared to many competitors, but if sleeping well matters more to you than achieving the lowest pack weight, the Disco is an easy bag to like.

Warmth / Weight

Warmth / Weight

2.5/5
Comfort

Comfort

4.5/5
Features

Features

5/5
Durability

Durability

4/5
Water Resistance

Water Resistance

4/5
Sustainability

Sustainability

4.6/5

Temp Rating

27/16°F (ISO Comfort/Limit)

Weight

2 lb. 14 oz.

Fill

1 lb. 7 oz. of 650-fill down

Shell

20D polyester

Shoulder/Hip Girth

62/57 in.

Packed Volume

14.9L

Other Temps

30F

Pros

Hourglass design gives you plenty of room to shift positions as you sleep.
Large zippered vents on the chest help with temperature control.
Footbox and hood fabrics are waterproof to fend off tent wall condensation.
It’s 100% recyclable at the end of its life, a nice sustainability bonus.

Cons

One of the heavier backpacking sleeping bags we’ve tested, tipping the scales at almost 3 pounds.
The 650-fill-power down is not as lofty, compressible, or light as higher-end bags.

For this season's top models, see our guide to the Best Backpacking Sleeping Bags.

At nearly 3 pounds, the Nemo Disco Endless Promise 15 is one of the heavier backpacking sleeping bags that Better Trail has tested in this temperature range. Its weight and bulk all but rule it out for fast-and-light trips, especially when you compare it to premium 15-degree bags like the Sea to Summit Spark (1 lb. 9.7 oz.) or Western Mountaineering Ultralight (1 lb. 13 oz.), which are far lighter—but, at more than $500, also far more expensive.


To break down the differences: Those models are stuffed with 850-fill down, but the Disco’s insulation is 650-fill, which is considerably less lofty. Lower fill power down is cheaper, but it also means that more of it is required to hit the sleeping bag’s ISO rating. To this end, the Disco 15 contains a whopping 1 pound 7 ounces of insulation, which helps explain its weight. That also means that the Disco is far larger when packed than the Spark and the Ultralight, so if you’re a minimalist hiker, this is not the sleeping bag for you. All in all, the Disco’s warmth-to-weight ratio is its biggest compromise, which Nemo makes in the name of comfort.


Weight aside, it is a genuinely warm bag. I tested the Nemo Disco 15 in an alpine hut next to a lake with high humidity, where overnight temperatures dipped into the low 30s, and I stayed warm the entire night while sleeping on a basic hut mat. Its oversized draft collar (which you can fold out of the bag or snuggle into like a blanket), draft tube, cinchable hood, and zippered chest make it easy to fine-tune warmth. I could vent without fully unzipping the bag, which helped prevent overheating while still sealing out drafts. It’s not a light bag, but it’s versatile across a wide range of temperatures.

Comfort is where the Nemo Disco 15 truly shines. The bag’s hourglass shape provides significant room at the shoulders (62-in. girth) and knees (61 in.) while narrowing at the hips (57 in.). This design is meant to reduce dead air that can make you cold while still granting plenty of space, and it works exactly as intended. As someone who switches sides frequently while sleeping, I immediately appreciated how unrestricted the bag felt. It offers far more freedom of movement than a traditional mummy shape without sacrificing too much warmth.


The spacious footbox keeps my feet from feeling cramped, and the silhouette feels more like a semi-rectangular bag (which you probably wouldn’t use for backpacking at all) than a mummy. Compared to other comfort-oriented backpacking sleeping bags I’ve used, including slimmer, side-sleeper-specific bags, the Disco strikes a much better balance between space and insulation efficiency.


The fabric on the Disco isn’t the softest I’ve encountered, and if you’re particularly sensitive to texture, a silk or cotton liner would add a noticeable boost in comfort. In terms of noise levels, they were typical for a down bag and nothing distracting. I also liked the baffle layout—vertical on the upper body and horizontal on the lower—which seemed to help the bag drape naturally as I shifted positions. Between the roomy cut, the cozy draft collar, and the customizable venting system, the Disco feels built for folks who want to thrive, not just survive, in the backcountry.

For a backpacking sleeping bag, the Nemo Disco 15 is unusually feature-rich, and it’s clear Nemo prioritized usability over minimalism. The standout feature is the Thermo Gill system, which is comprised of two zippered vents near the torso with both internal and external zippers. When opened, they expose a jersey mesh that releases heat without letting cold drafts rush in. I haven’t used another bag with this kind of ventilation, and it genuinely works.


The oversized “Blanket Fold” draft collar is another highlight. I could flip it outward on warmer nights to encourage airflow or tuck it in tightly when temperatures dropped. The hood is fully cinchable and paired with a full-length draft tube along the zipper to seal in warmth.


There’s also a small pillow barn in the hood designed to hold a backpacking pillow or extra clothes. It’s a tight fit—you’ll want to insert your pillow before inflating—but once set up, it kept everything in place. Last but not least, Nemo includes a proper compression sack with four straps, which lets you shrink the bag down to roughly the size of a small volleyball. It’s heavier than a basic stuff sack, but it matches the bag’s comfort-first philosophy.

The Disco feels notably more durable than most down backpacking sleeping bags I’ve used. It’s made with a 20-denier recycled ripstop polyester shell with a durable water-repellent (DWR) finish, and is thicker than the fabrics found on many premium ultralight 15-degree bags. I never felt like I needed to baby it.


The reinforced hood and footbox stood out as well. They’re built with an extra layer of fabric that’s also covered with a waterproof coating. The bag’s head and foot are what move around the most and can potentially snag most frequently, and they also come into contact with tent walls wet from condensation; the reinforcement helps keep those areas rip-free and dry. Finally, the Disco’s anti-snag zippers worked fine—nothing remarkable, but no issues during testing.


All in all, the Nemo Disco inspires more confidence than most other backpacking bags I’ve used. While it’s heavier than I’d prefer, the added durability makes the weight feel more justified, especially for weekend trips where comfort and longevity matter more than ounce-counting.

For a down sleeping bag, the Nemo Disco 15 does a commendable job managing moisture. The shell fabric is treated with DWR, and Nemo reinforces the hood and footbox with a PFAS-free waterproof material. Those areas are especially prone to condensation in small backpacking tents, and the added protection makes a real difference between a soggy sleep and a dry, cozy one.


The Disco also contains hydrophobic down, which helps prevent moisture absorption and clumping. Of course, it’s still a down bag—if it gets truly wet, performance will suffer—but for dealing with tent condensation and damp environments, the Disco feels more resilient than many competitors. If you think your trip is going to be absolutely sodden, though, and that your bag may get wet, go with a synthetic option like the Marmot Trestles Elite Eco.

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Longevity

Choosing durable outdoor gear and keeping it in use for longer is one of the best ways to reduce environmental impact. Our proprietary longevity rating assesses factors like overall build quality, materials, fabric denier, component durability, and real-world performance. A green check indicates that we expect the product to be long-lasting relative to its peers, a yellow check mark indicates average longevity, and a red X indicates a product that may have a limited lifespan.

I’m 5-foot-8, and I tested the Disco in the men’s regular size, which is rated for sleepers up to 6 feet tall. The fit was roomy, but that’s the point, and the Disco lands somewhere between a trim mummy bag and a semi-rectangular design. There was plenty of space at the shoulders and legs, which contributed heavily to the bag’s comfort.


Nemo offers a broad range of sizes, including Regular Wide, Long, and Long Wide options for men, as well as multiple women’s-specific cuts. If you know you want extra room, the Wide versions provide a lot of space without pushing the bag into full rectangular territory.


If you’re coming from a slim mummy bag, the Disco will feel spacious immediately. That extra room is a big part of its appeal—but also part of why it weighs what it does.

Big Agnes Sidewinder 20 ($330): A More Specialized Bag
The Sidewinder 20 is purpose-built for side sleepers, with a centered zipper that prevents rolling onto it during the night. While its shoulder girth is similar to the Disco’s, it tapers aggressively at the feet, offering far less room overall (whereas the Sidewinder is meant to turn with you, the Disco is roomy enough that you can turn inside of it). Both bags use 650-fill down, but the Disco packs in more insulation to achieve a slightly warmer ISO rating—at the cost of additional weight, though. Where the Disco really pulls ahead is features: The draft collar, vents, pillow pocket, and reinforced hood and footbox all help justify its higher price and weight. In the end, the Sidewinder feels more niche; the Disco feels more versatile. To learn more, check out our Sidewinder SL 20 review.


Nemo Riff Endless Promise 15 ($400): An Identity Crisis
The Riff shares the Disco’s hourglass shape and many of its best features, but upgrades to 800-fill down, trimming about 4 ounces off the total weight. It’s still over 2.5 pounds, though, and the packed size difference is negligible, so this is also a sleeping bag for relaxed backpacking trips rather than long-distance epics. The Riff also costs $100 more. In terms of interior space, the Disco offers noticeably more, particularly at the hips and knees, and feels more relaxed overall. Unless shaving a few ounces is a high priority for you, the Disco delivers better value, more room, and nearly identical warmth. For more, read our review of the Riff Endless Promise 15.

Nemo Disco 15 ($300)
Nemo Disco Endless Promise 15 backpacking sleeping bag logo and product name
4.3/5

With an hourglass shape that provides plenty of room at the shoulders and knees, the Disco’s dimensions are a boon for side-sleepers. Ultra-soft materials and zippered vents add to the comfort-first design—at the expense of some extra weight.

Temp Rating
27/16°F (ISO Comfort/Limit)
Weight
2 lb. 14 oz.
Fill
1 lb. 7 oz. of 650-fill down
Shell
20D polyester
Shoulder/Hip Girth
62/57 in.
Packed Volume
14.9L
Other Temps
30F
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Warmth / Weight

2.5/5
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Comfort

4.5/5
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Features

5/5
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Durability

4/5
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Water Resistance

4/5
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Sustainability

4.6/5
Big Agnes Sidewinder 20 ($330)
Big Agnes Sidewinder SL 20 Sleeping Bag temp rating
4.2/5

The purpose-built Sidewinder is made for one specific group of backpackers: those who sleep almost exclusively on their sides. However, it’s not for everyone, and is middling in weight and packability.

Temp Rating
30/19°F (ISO Comfort/Limit)
Weight
2 lb. 7 oz.
Fill
15 oz. of 650-fill down; 6.5 oz. synthetic
Shell
Polyester
Shoulder/Hip Girth
61/55 in.
Packed Volume
14L
Other Temps
0F
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Warmth / Weight

3/5
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Comfort

4.5/5
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Features

3.5/5
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Durability

3.5/5
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Water Resistance

3.5/5
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Sustainability

3.7/5
Nemo Riff 15 ($400)
Nemo Riff Endless Promise 15 Sleeping Bag's logo
4.2/5

The Riff pairs nominally weight-saving materials with a comfort-minded mentality, but the results aren’t spectacular. This bag feels great, but we wish it leaned into either its roominess or packability even more.

Temp Rating
28/17˚F (ISO Comfort/Limit)
Weight
2 lb. 10 oz.
Fill
1 lb. 3 oz. of 800-fill down
Shell
Polyester
Shoulder/Hip Girth
60/54 in.
Packed Volume
10.8L
Other Temps
30F
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Warmth / Weight

3/5
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Comfort

4.5/5
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Features

5/5
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Durability

4/5
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Water Resistance

4/5
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Sustainability

4.5/5

Is the Disco 15 for You?

If you place a high premium on sleeping bag comfort (and to be honest, who doesn’t?), want room to move around while you sleep, and like smart temperature regulation—and you’re willing to carry extra weight to get it—the Nemo Disco Endless Promise 15 is a great sleeping bag choice. It’s ideal for weekend backpackers, side sleepers, and anyone who dislikes the restrictive feel of mummy bags. Given its hefty weight, it’s not a thru-hiking or ultralight specialist, but for shorter trips that are more about laid-back fun than obsessing about mileage, the Disco is an inviting bag to retire into at the end of the day.

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