Well, normally I'd say 2 7950's OC'd beats 2 660ti's OC'd, but if they're factory OC'd, that probably (but not definitely) means their PCB's are better than other 660ti's (which is why they were picked to be factory OC'd in the first place). Get the 2 660ti's then. They'll use less power and produce less heat in the process.
So in this case the whole single monitor = get Nvidia, multimonitor = get AMD doesn't count for much?
I swear I get such conflicting information on the internet haha
well the 7950 is more expensive than the gtx 660ti and not faster only u overclock it heavily and even than, its still close battle.