Riff 15 Endless Promise vs REI Magma 15
Head-to-head sleeping bag comparison.
| Riff 15 Endless Promise | REI Magma 15 | |
|---|---|---|
| Brand | NEMO Equipment | REI Co-op |
| Price | $399 - $450 | $369 - $429 |
| Rating | 4.4 | 4.6 |
The Bottom Line
If you want the lightest, most compressible, and warmest-for-its-weight three-season bag, pick the REI Co-op Magma 15—it’s the winner for thru-hikers and weight-conscious backpackers. If you’re a side sleeper, run warm, or prioritize roomy livability and venting over shaving weight, the NEMO Riff 15 is the smarter, more comfortable choice. Stop comparing them as equals—Magma is the efficiency pick; Riff is the comfort pick.
Weight & Packability
The REI Co-op Magma 15 wins outright on weight and stuff-sack footprint: at roughly 1 lb 12 oz and a 5.2 L compressed volume it disappears in your pack, whereas the NEMO Riff 15 sits a full half-pound to a pound heavier and compresses to roughly 6.9–9.5 L depending on length. On the trail that translates into more room for fuel, food or lighter pack frames with the Magma, while the Riff forces you to accept a small weight and volume premium for livability. If grams and space matter for long miles, take the Magma; if you carry a bit more or camp-car, the Riff's bulk is tolerable for what you get back in comfort.
Value & Who Should Buy Which
Choose the REI Co-op Magma 15 if you prioritize warmth-to-weight and pack space for three-season backpacking—it’s the right call for mileage-focused backpackers who want premium 850-fill insulation without cottage-brand prices. Choose the NEMO Riff 15 if you value sleeping comfort, side-sleeper room, and on-the-fly temperature control—it's the better buy for weekend warriors, car campers, or anyone who sacrifices a few ounces for better sleep. These aren’t interchangeable: buy the Magma to chase miles and low bulk; buy the Riff to sleep better and stay comfortable in variable shoulder-season conditions.
Zippers, Venting & Usability
NEMO’s Riff 15 wins on ventilation and living-in-the-bag usability thanks to its full-length 2-way zipper plus Thermo Gills and a draft collar—features designed for on-trail temperature fiddling and side-entry comfort. The Magma 15 keeps things simple and efficient with anti-snag zippers, a zipper draft tube, and a vaulted footbox that preserves warmth with less fabric, but it lacks the Riff’s venting options, so it can feel stifling on warmer nights. If you want to unzip a little, ventilate quickly, or sleep semi-upright without dumping heat, the Riff makes life easier; if you want fewer moving parts and a clean, tight seal against cold, the Magma’s approach is neater and lighter.
Fit, Sleep Position & Livability
The NEMO Riff 15 is the clear winner for side sleepers and anyone who hates feeling hugged by their bag—the spoon-shaped cut gives real elbow and knee room and reduces the cramped feeling common in mummy bags. The REI Magma 15 trades that space for efficiency: its classic mummy shape hugs you closely to save weight and retain warmth, which is ideal for back sleepers and people who don't move much overnight. If you toss and turn or want to wear clothing and move inside your bag, the Riff is worth the weight penalty; if you sleep straight and want minimalist dead-space, take the Magma.
Materials, Durability & Weather Resistance
REI wins on loft-per-ounce with 850-fill goose down and a very lightweight 15D Pertex Quantum shell that keeps the bag compressible and efficient, while NEMO leans heavier-duty with a 20D ripstop shell and 30D taffeta lining that feel stiffer but more abrasion-resistant and slightly more water-shedding in real use. The Riff also shoots ahead with a water-resistant footbox and robust DWR on both shell and lining, which makes it marginally more forgiving in damp camps; the Magma’s down is treated and bluesign/RDS-certified, so it resists moisture too but trusts lightweight fabrics over heavier durability. Put simply: Magma is optimized for weight and treated down performance, Riff is optimized for rugged comfort and a touch more real-world wet-weather forgiveness.
Warmth, Insulation & Temperature Management
Both bags claim a 15°F lower-limit, but they get there with different philosophies: the Magma 15 uses 850-fill goose down to maximize warmth-to-weight, so it feels objectively warmer per ounce and is the winner if your priority is squeeze-out warmth for cold shoulder-season nights. The Riff 15 uses 800-fill down and loses a little thermal efficiency to its roomier spoon shape, but it fights back with Thermo Gills—zippered vents that let you dump excess heat without unzipping the whole bag—making the Riff the better real-world choice if you tend to run hot or need variable temperature control. In plain terms, Magma is the warmer-for-the-weight option; Riff is the better temperature regulator for active sleepers or variable conditions.
Reliability, Version History & Failure Modes
REI’s Magma has had iterative updates—changing fill weights and sizing—so expect consistent lightweight performance but keep an eye on year-to-year spec changes; its thin 15D shell means it will show wear sooner if you’re rough with it. The Riff’s market notes of discontinued listings and mixed spec reporting point to some version confusion, but its heavier 20D/30D fabric and simpler mechanical venting mean damage usually shows up as scuffs or zipper wear rather than catastrophic down loss. In practice: Magma can deliver factory-tight warmth until the shell wears, while the Riff’s more conservative materials and user-friendly vents are easier to live with when you camp dirty or variable.
Read full Riff 15 Endless Promise review · Read full REI Magma 15 review