I am debating between MSI N670PE/OC & EVGA GTX 670FTW as well.
On the one hand PE have a better Stock clock(worse boost block on paper but I read review where it auto boost into the 1.1-1.2 Ghz range on its own which surpasses FTW) and is custom fan cooled(heats up mobo but keep itself cool, need open air case), on the other hand EVGA have better boost clock, is $5 cheaper(plus don't have to worry about the rebate), and backed up by EVGA's customer service system + the Step up program+ Blower cooled(you can set up fans to help it cool/don't dirupt positive air flow design).
If there is a review where they went head to head it would be easier to decide but so far I haven't found one, popularity wise I see EVGA outselling MSI by a mile. I am not that interested with the Gigabyte as their stock clock is below Ghz.