Look in the FAQ on the WM website. They list a large number of their bags EN ratings.Well it’s hard to tell what WM actual rating is. According to their website, it’s “somewhere between comfort and limit.” So if it’s rated at 0* and that’s between comfort and limit assume the comfort is maybe 5ish*? The comfort on the Marmot is 9* and I’ve had it lower than that and been plenty toasty, but I am a warm sleeper and I like the tight cut. I’m not implying they are the same, but for a $600 difference, based on my real world use of the Marmot, I would recommend it not to be over looked.