I hammock camp when I bike and when I ride my motorcycle. I get cold from the bottom in anything below 60 degrees, but find that a car windshield sun screen with mylar cover allows me to sleep comfortably down to 50 degrees. That was with a 60 degree bag (yes 60) and a fleece jacket on and long pants. I do not like to bring too many bulky items so sometimes I am uncomfortable. That for me is outweighed by the ease at which I pack up my camp, ride my bike (lighter), and don't have things strapped on or hanging off the motorcycle waiting to get stolen when I want to go into a restaurant, etc.

Also, I don't have a convenient place to put my tent poles on either the bike or motorcycle so I go with the hammock.