Like my son I can normally sleep anywhere and in any position, though I prefer sleeping on my side. I have some trouble normally in a banana hammock.
I find the HH asym models, my bridge bag and my my asym net hammock allow me to move around a lot, especially the HH. Without the side ties, the net hammock is like lying on a rope and I can't get comfortable at all.
I think it is something about the stability, rather than the room to spread out, as last night I disconnected one side of the asym net hammock and bungeed it over the other and slept well in the net cocoon.