I am having a hard time deciding on which bag to use on the CDT. I have a marmot hydrogen, a marmot helium, a golite ultra 20, and a golite ultralight 3 season. I know, I know, I have a down fetish and the differences are not all that great. I don't sleep cold, and usually carry a down sweater and have been comfortable in the hydrogen and the ultra 20 to the mid twenties. But then again I would rather be a little warm than a little cold. Hydrogen and ultra 20 are lighter by 6-8 oz and have been my go to bags, but I see many using warmer bags on the CDT. Any wisdom?