So I need to buy a new sleeping bag for my wife and I'm trying to decide between the Western Mountaineering Versalite or WM Ultralite. My problem is that the spec's aren't making sense to me, so maybe someone can point out what I'm missing.
According to WM's website, the Versalite has an extra 4oz of down and the cut is several inches more generous, yet it only weighs 3oz more. How could this be when everything else is the same (#5 zip, 850 down, baffle spacing, 0.9oz fabric)? Looking at how the cut affects weight on other WM bags (ie. Alpinlite vs. Ultralight), you would expect the cut of the Versalite to add about 1 to 1.5oz of weight, so with the extra down and wider cut you would expect the Versalite to come in about 5 to 5.5oz heavier, not 3oz.
I kinda think the Ultralite is the way to go, but my wife loves her bags warm and adding 3oz for -12 C rated bag versus -7 C is tempting because she'll be upset if I buy her a new bag that she's cold in. Her previous bag was -10 C rated (MEC Merlin) and it ended up being warranted today for a full refund (MEC warranty rocks).
Alternatively, I'm open to suggestions for other bags but it needs to be -7 to -12 C (10-20F) rated and top notch down and lightweight shell fabrics. I may look at Montbell and Feathered Friends.