There are a whole lot of people who think hammocks are very comfortable indeed, and wouldn't go without them.

I sleep on my side, on my back (only in the hammock), on my side and back (only in the hammock), sometimes with my knee bent, sometimes with both knees bent... I only know this if something happens to wake me up at night and I can catch myself in whatever strange position I've rolled into. I've found (like others have said) that a hammock lets you sleep in positions you previously found intolerable. No pressure points. In bed I'm always on my side, no variation.

I did mention I'm claustrophobic - if it were like a barrel I wouldn't have one. Whenever the weather is good I leave the tarp pulled back so I can look at the sky. When it rains I have more space than in a solo tent to change clothes, cook, and hang gear. A trash bag I use as a pack liner makes a nice place to stand in sock feet while arranging gear and getting ready for bed, and on a recent trip I was the only one not drying my sleeping bag (quilt, actually) in the sun the morning after 18 hours of rain. So I do find the hammock quite comfortable.

You might have a look at hammockforums.net if you are interested in finding out about all the different kinds of hammock and the ways people use them.