A close look at two sleeping bags buyers cross-shop. The Sonic 0 leans on low weight while the Bishop Pass Windstopper 0F answers with warmth, so the pick comes down to which you value.
| NEMO Sonic 0 | Mountain Hardwear Bishop Pass Windstopper 0F | |
|---|---|---|
| GearScore | 79✓ | 77 |
| Comfort rating | 14 °F | 13 °F✓ |
| Weight | 3 lb 4.0 oz✓ | 3 lb 4.7 oz |
| Warmth-to-weight | 3.8 /100g | 3.8 /100g✓ |
| Packed size | 9.6 L✓ | 12.9 L |
| Fill power | 800 FP✓ | 650 FP |
| Price | $600 | $560✓ |
| Fill | Down | Down |
| Style | Bag | Bag |
| Shape | Mummy | Mummy |
Highlighted cells mark the better spec: Sonic 0 in blue, Bishop Pass Windstopper 0F 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 NEMO Sonic 0 next to the Mountain Hardwear Bishop Pass Windstopper 0F and the trade-offs are clear. The Sonic 0 wins on low weight and packability, and the Bishop Pass Windstopper 0F pushes back on warmth and warmth-to-weight.
The Sonic 0 is 1 oz lighter, more packable (9.6 L vs 12.9 L), and higher fill power (800 vs 650). The Bishop Pass Windstopper 0F is warmer (rated 13°F vs 14°F), stronger on warmth-to-weight, and $40 cheaper. On the default GearScore the Sonic 0 leads 79 to 77.
Pick the Sonic 0 if you care most about low weight and packability, which makes it the better call for counting grams on long miles. Pick the Bishop Pass Windstopper 0F if warmth and warmth-to-weight matter more to you, or you are focused on colder nights and shoulder-season trips.
The NEMO Sonic 0. It is 1 oz lighter than the Bishop Pass Windstopper 0F.
The Mountain Hardwear Bishop Pass Windstopper 0F. It is warmer (rated 13°F vs 14°F) than the Sonic 0.
The NEMO Sonic 0, 79 to 77 on the default algorithm. You can re-weight the factors to match your trip.
It depends on your priorities. Go with the Sonic 0 for low weight, or the Bishop Pass Windstopper 0F for warmth. The spec table above shows exactly where each wins.