Homeseer has updated their comparison charts of switches, they now have two different pages, one for relay type, one for dimmable. I always used their chard to compare, now they have them split by function. (Okay so it may not cover every brand, but you get the idea) I think this is new, last time I looked it was all on one page…
http://store.homeseer.com/store/HomeSeer-Z-Wave-OnOff-Wall-Switch-Matrix-W7.aspx
http://store.homeseer.com/store/HomeSeer-Z-Wave-Dimming-Wall-Switch-Matrix-W16.aspx