I just sail a F16 solo downwind with enough mainsheet tension to protect the mast. However, I find it better/easier with enough wind to keep the windward hull flying higher than usual, it looks better in the photo's for starters and the other reason is because (and I'm sure to be corrected) I feel that it produces more buoyancy in the leeward bow! To me it feels as if I've changed a displacement hull into a plaining hull by the heel of the boat.
Fire away...........I also capsize (occasionally)
I'll probably answer the sail, drag question the day before I hang up my harness which I hope wont be for a long time <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />