If out of the three cards, I wanted to leave everything at stock speeds and do not plan on OCing at all, which card would be the best? Meaning if I just wanted the lowest temperatures & best performance at stock speeds... would the XFX reference still be cooler and better? Would it not be until I do some heavy OC'ing then the XFX reference card be better? My understanding is that reference cards push air out of the case while non-reference pushes half out and half in (perhaps to make the GFX itself stay cooler?), but I would also want my CPU to stay cool as well.
Your going to get different answers on all 3 because of a individuals case , ambient temperature. But at stock they are all going to perform very close to each other. Unless someone owns all three and can test themselves your only going to get opinion. They are DEFINITELY that close/similar. There is no bad egg.