this is the 100 EURO difference between the 660 ti and the 670. I have seen 660 ti playing bf3 on extra smoothly, so its capible of doing it, but i just dont know when you will notice the 192 bit bus..
and that is what i think the "forgot the word something like competator" from amd, as you can see the 7950 will do better in crysis, and 660 ti better on bf3 and portal, but the rest they are pretty even.. same for the prices ( in holland ), 660 ti might even be about 10 euro's lower
so for me as bf3 player i would buy the 660 ti, and if you have enough money you can buy the 670 that in my case adds 10 fps on bf3..
The reasons i would by the 660 Ti is because its pretty cheap for the amount of performance it gives. About £100 cheaper for a slight memory bus difference that can be resolved with a nice, high overclock on your memory. After all, overclocking is free!
Depends on whether you want to overclock or not. They seem pretty similar at stock but I'm pretty disappointed with the high stock GPU clock on the 660 which is a lot higher than the 7950.