I didn’t like the El Coyote because of the weak drawstrings…moving around at night, I’d work the footbox open a little, which obviously sucks in the cold. The Katabatic was great, just could have used two more inches in width. The sewn footbox of the Enigma is my strong preference for cold weather use, and it’s available in wide and extra wide versions.
I haven’t tried the cold weather double straps, and probably won’t get the chance now. I’m good to about 15 with my current quilt and can get a little lower with the right clothes, but if I ever have a need to camp in single digits, I’ll look into an entirely different setup.