I'm very happy with my Speer.
I can side sleep, or mostly side sleep, kinda a modified, but very comfortable. I have to leave a lot of slack, then sleep slightly diagonal to accomplish this, just as Ed Speer recommends. I find I toss and turn much less in the hammock than on the ground.
For testing purposes, you should probably wait until summer to do your trials, then you don't have to invest in any extra insulation. A closed cell pad and any old sleeping bag used as a quilt will work. This will let you know if you find hammock sleeping comfortable, my guess is you will.
I'm not an expert, and I'm sure others will chime in, but this is my $0.02 worth (possibly all it's actually worth!) :-)