A close look at two sleeping bags buyers cross-shop. Both are solid; the right one depends on the specs you care about most.
| Marmot Helium 15 | Rab Neutrino Pro 500 | |
|---|---|---|
| GearScore | 84✓ | 65 |
| Comfort rating | 27 °F | 26 °F✓ |
| Weight | 2 lb 2.7 oz | 2 lb 0.3 oz✓ |
| Warmth-to-weight | 4.4 /100g | 4.8 /100g✓ |
| Packed size | 9.2 L | n/s |
| Fill power | 800 FP | 800 FP |
| Price | $499 | n/s |
| Fill | Down | Down |
| Style | Bag | Bag |
| Shape | Mummy | Mummy |
Highlighted cells mark the better spec: Helium 15 in blue, Neutrino Pro 500 in amber. A blank spec is never counted as a win. A lower comfort rating in °F means a warmer bag, so the warmer bag takes that row. GearScore is the overall rating (0 to 100); re-weight it on the full bag comparison. Prices are current MSRP.
Put the Marmot Helium 15 next to the Rab Neutrino Pro 500 and the trade-offs are clear. The Helium 15 wins on balance, and the Neutrino Pro 500 pushes back on warmth and low weight.
The Neutrino Pro 500 is warmer (rated 26°F vs 27°F), 2 oz lighter, and stronger on warmth-to-weight. On the default GearScore the Helium 15 leads 84 to 65.
Pick the Helium 15 if you care most about the overall package. Pick the Neutrino Pro 500 if warmth and low weight matter more to you, or you are focused on colder nights and shoulder-season trips.
The Rab Neutrino Pro 500. It is warmer (rated 26°F vs 27°F) than the Helium 15.
The Rab Neutrino Pro 500. It is 2 oz lighter than the Helium 15.
The Marmot Helium 15, 84 to 65 on the default algorithm. You can re-weight the factors to match your trip.
It depends on your priorities. Go with the Helium 15 for the overall balance, or the Neutrino Pro 500 for warmth. The spec table above shows exactly where each wins.