Pretty much was my line of thinking a few months ago.
It worked pretty well for me, it doubled my frame rate in GTA from an average of about 44 to 82 with increased settings, and a bunch of other games ran much smoother.
The extra 3GB of framebuffer help a ton, but to my knowledge the 7950s pretty much all were 2gb which is pretty rough to work with for modern games.
If you have a good enough power supply for it I'd say go for it.