I've always used warm and natural. For me it was easier to quilt with. And I found great buys on it at Joanns. It is really warm batting. But, when my supply of warm and natural is gone, I'm going to switch to Hobbs 80/20. I like the crinkle look it gets when you wash and dry it. It's also nice and warm. Will be watching to see what kind of replies you get on this subject.
For the most part, I lived in Florida and didn't need such heavy batting. But, now I live in KY and it's cold here. My bed is layer with 2 quilts and I'm nice and toasty warm. (Both quilted with warm and natural batting.)