Here is how these two sleeping bags compare on the numbers. On the data the Swallow YF 20 is the stronger all-round pick, and the question is whether the UltraLite still fits your budget or priorities.
| Feathered Friends Swallow YF 20 | Western Mountaineering UltraLite | |
|---|---|---|
| GearScore | 86✓ | 66 |
| Comfort rating | 30 °F | 30 °F |
| Weight | 29.2 oz | 29.0 oz✓ |
| Warmth-to-weight | 4.8 /100g | 4.9 /100g✓ |
| Packed size | 9.0 L | n/s |
| Fill power | 900 FP✓ | 850 FP |
| Price | $589✓ | $630 |
| Fill | Down | Down |
| Style | Bag | Bag |
| Shape | Mummy | Mummy |
Highlighted cells mark the better spec: Swallow YF 20 in blue, UltraLite 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.
The Feathered Friends Swallow YF 20 against the Western Mountaineering UltraLite is a study in priorities. The Swallow YF 20 is the stronger pick on most of the specs that matter, while the UltraLite makes its case on low weight and warmth-to-weight.
The Swallow YF 20 is higher fill power (900 vs 850) and $41 cheaper. The UltraLite is 1 oz lighter and stronger on warmth-to-weight. On the default GearScore the Swallow YF 20 leads 86 to 66.
Pick the Swallow YF 20 if you care most about fill power and price, which makes it the better call for your priorities. Pick the UltraLite if low weight and warmth-to-weight matter more to you, or you are focused on counting grams on long miles.
The Western Mountaineering UltraLite. It is 1 oz lighter than the Swallow YF 20.
The Feathered Friends Swallow YF 20. It is higher fill power (900 vs 850) than the UltraLite.
The Feathered Friends Swallow YF 20, 86 to 66 on the default algorithm. You can re-weight the factors to match your trip.
The Swallow YF 20 is the stronger all-round pick here. Choose the UltraLite if low weight is your priority.