I have the Atwood 1200 BTU heater. It's great, liking having a camp fire. I crank it up at night before going to bed and in the morning before getting up. Hell, I've camped on Denali at -20F. At night I turn it off and sleep in my bag, normally a 32 deg mountain hardware phantom. I also have a 45 deg, 20 deg, 0 deg, and -20 deg bag if needed. Normally I just unzip the bag and use it as a cover. But the heater is nice on those rainy evenings or cold mornings before I get the coffee going, or if you stay up late to catch the Milky Way.