I run the Shiva and Burn, both in M. The Shiva comes out for anything overnight or very vertical, and the Burn for low water, long hikes (it is 10 lbs lighter) or big water. Both will do what the other does, but they each have their strong suits that I like to play to.
I think I can boof bigger in the Shiva, which is good because landing flat in the Burn does hurt. It is easy to switch edges mid-air in both, but easier to kick down the nose of the Burn. The Burn tracks much better in pushy water, while the Shiva's nose gets pushed around a little. The Shiva is a much faster boat in a straight line. With the Burn you need to be very careful about facing your hull to the current, and it loves to be thrown around. Aggressiveness is rewarded with that boat with you are coming into an eddy: put the nose in at the top of the eddy, crank it over to 60', put the paddle blade at the top of eddy and call your chiropractor for the whiplash.
As for the others, I'm not a fan of the Villain, Nomad, Jefe or Stomper. They just don't hook into eddies the way I like. I love knowing that I will stop in that eddy just above certain doom.