I found this thread very interesting. (I have a double, with gathered ends) I'm still trying to find my perfect "lay" to be able to sleep all night. In my bed I'm a belly sleeper most of the time and a side sleeper with a leg pillow between my knees. For laying in the hammock I liked more of a banana shape for the first couple of hours....but then my lower back starts to hurt. When I lessen the sag, I don't like how tight the sides become and what's weird is that I wake up in the middle, on my side at a severe diagonal (almost the entire wrong direction) with...of course my shoulder that I'm laying on and neck hurting like hell (I don't start out in the position). I understand everyone is different; but this sure is taking me awhile to figure out. I think some of my issue is just being used to sleeping on my belly for almost 42 years...and not being able to figure out how to sleep a different way. There is no way with my knees that I would be able to belly sleep in the hammock I have. The not to sag, or to sag, and how much sag is quite a learning curve on my end. Very frustrating!
Now my son on the other hand likes a big sag, and sleeps sound, on his side in the fetal position right in the very middle of the hammock where the sag is. Looks like a big ball of blanket laying in the middle. I would think the angle would hurt his ribs and neck...but he says it's great. He may be 13, but he is 150 lbs and 5'9" now and I'm surprised at how he sleeps in his hammock. His ridge line is probably only 65 -70"...I would have to check that. The banana works very well for him.