+1 to an UQ being most comfortable.
A bridge hammock may help. I never sleep on my back for long, except in my JRB BMBH. I sleep on my side, and toss'n'turn most of the time wherever I sleep.
However, I sleep on the ground a lot. A NeoAir (or other inflatable) makes for comfy side & back sleeping. My pack is lighter when I go to ground, too (Although some get lighter in the trees).
Don't tie yourself to the ground or to the trees just because you like the idea (been there). Use the setup and technique that gets you into the woods most - whichever that may be.
-- Funny Money
Love 'em while you got 'em