670 spend less watts to do the same job. the new Nvidia 670 is the 760.
try find the 760. when u look to a gaming card is better you know how it will drain your watts and your money. 30 fps is good to play a game. 60 fps is great more than that if only you have a 120hz TN panel to do the job.
The GTX 760 is marginally cheaper but with Nvidia bringing out the 760 Ti wouldn't that, make any purchase of the 760 now a waste?
Depends on what kind of performance you are trying to get. The 280x will be stronger than a 760 ti. The 760 ti is just a 670. A 670 is a bit stronger than a 760.
-The 280X is newer and more powerfull, and clearly better having 288 GB/s memory bandwidth, DirectX 11.2, 2048 pixel and vertex shaders compared to 1344 from GTX670..
-So Im sure you have your answer already.
A 270x with a healthy overclock is comparable or minimally behind a 670. Thus the 280x will be superior in most applications.
The 280x is grossly overpriced right now, however, due to this damned rampant crypto-currency speculation. I would wait to pull the trigger on one of these. Hopefully the whole game goes bust and we see a glut of slightly used 280x's on the market at bargain prices.