NEMO Riff 15 vs REI Co-op Magma 15
In short: The REI Co-op Magma 15 costs $1 less; the NEMO Riff 15 is rated 4 °F colder on the figure each maker publishes; the REI Co-op Magma 15 saves 5.0 oz.
| Spec | NEMO Riff 15 | REI Co-op Magma 15 |
|---|---|---|
| Approx. price | ~$400 | ~$399 |
| ISO comfort | not published | 21 °F |
| ISO limit | 17 °F | 9 °F |
| Rating on the label | 15 °F | 15 °F |
| Honesty gap | — | 6 °F |
| Rating standard | ISO 23537 | ISO 23537 |
| Weight | 2 lb 7 oz | 2 lb 2 oz |
| Warmth per ounce | — | 1.15 °F/oz |
| Fill | 800 fill power down | 850 fill power down |
| Fill weight | not published | 23.3 oz |
| Loft budget | — | 19.8k in³ |
| Shape | mummy | mummy |
| Shoulder girth | not published | not published |
| Zipper | full | half |
| Shell fabric | Recycled polyester ripstop, C0 DWR | 15D recycled nylon ripstop |
| Hydrophobic down | Yes | Yes |
| Packed size | 6.2 L | not published |
Shaded cells mark the row where one has a measurable advantage. Weight, thickness, girth and shape are left unshaded on purpose: heavier is sometimes tougher, wider is sometimes warmer, and calling a winner on those would be an opinion dressed as a measurement.
What each one does well, and costs you
NEMO Riff 15
- 800-fill down cuts four ounces and half a litre off the Disco at the same rated temperature.
- Keeps the Spoon shape, so it is still the side sleeper's bag — just a trimmer version of it.
- ISO lower limit of 17 °F published.
- Thermo Gills let a warm night be survived without unzipping the whole bag.
- $400 against the Disco's $300 for four ounces — the most expensive ounces in this catalogue.
- Only two lengths and no wide option, unlike the Disco's four sizes.
- Like every NEMO bag here, the ISO comfort figure is not published.
- The trimmer cut undoes some of the Spoon's point if you were buying it for room.
REI Co-op Magma 15
- Publishes both ISO figures, and the comfort rating of 21 °F is only six degrees off the name — the smallest gap in this catalogue.
- 23.3 ounces of 850-fill hydrophobic down for $399 is the most insulation per dollar of any down bag here.
- Half-length zip with a draft tube and a full draft collar, in a 15-denier recycled shell.
- Sold through a co-op with a real returns policy, which matters for a bag whose fit you cannot judge in a photograph.
- 34 ounces is heavier than the premium 20-degree bags, though it is also a colder bag than they are.
- REI does not publish shoulder girth, so the fit has to be judged in a store.
- The size run is not fully tabulated here — only the Regular's figures were verifiable from published sources.
- Retail-channel only, so there is no built-to-order width or overfill option.