It depends on the gun and the size of your hand. I have paws, not hands, and like the pachmayer grippers with the covered back strap. They fill my hand better. The Pachmayer professional series has an open back strap. The Hogue is comparable to the professional series.
If your right thumb is getting barked up it could be you need one of the special under cut thumb pieces (for opening the cylinder) Ed Brown makes them and Smith stocks them.