Hello,
I had the GTX 770 for a week, so I haven't done extensive testing. However I did play Skyrim and WoW while I had it. Skyrim I did not play any mods, but stock it generally ran it at 60fps, this was with maxed graphics. Very rarely did it drop below during "busy" scenes.
I didnt run fraps while I was on WoW but it had to be at 60fps, it played very smooth, no issues what so ever. That includes being in battlegroups, LFR 25's and hanging in capitals.
If you're buying it from somewhere that has a return policy, test it out in your set up and see if it gives you the desired results. From say like Amazon, you can return it for free. Newegg too but it takes a bit longer from personal experience.