My Gigabyte have been rock solids so far. (5x) The only things I would consider a 750ti without 6-pins connector. With five GPU I don't have any more 6-pins or molex connector I can safely use.

I was thinking of getting something without the 6 pins, but my X58 mobo doesn't really have any supplementary power for the PCI-X slots, would this matter at all? If running 3/4 cards?
I've got 3x EVGA 750Ti's on my X58 (no risers) with the TDP unlocked, +12mv, +151 GPU clock and the board is rock solid. I'm not doing scrypt/nscrypt though and haven't tested long term with it, short term it works and there is no burning smell