There are benefits to raftups and benefits to solo anchoring with friends nearby. Craig raises a good point about "like-minded" in a raftup. If you're an inside boat, you're unable to break away at ease. It makes for a much more harmonious experience.
We always raft up with our transoms aligned to allow easy movement from swimstep to swimstep. Organization and plenty of anchors is the key. We prefer an area free from weeds and current, every boat with a bow anchor and every other boat with a stern anchor.
Here are a couple of our raftups from our Delta trip last summer with TFers Giggitoni, Cpseudonym and Astral Blue.