The only thing I’m wondering is which 15 degree bag has a larger inside. Which is roomier. I know that makes a bag sleep cooler and I’m fine with that, this doesn’t have to be a real cold weather bag. I’m looking for which bag has more shoulder space and foot box room. Looking at the stated dimensions it looks like the WM is a tad bigger, but ive only been in the chilkoot. A 6’ long bag is all that’s needed.