The game ran excellent for me after getting a 7900GTX but when there was a lot going on or the server was packed my 2.5Ghz Athlon 64s (single or dual core... didn't really matter) would slow it down a little.
Its perfect now though.
I can play at 2048x1536 with 4x Super Sampling, 16x AF and vsync on and get 85fps constant all the time.
The increase in my minimum framerates with this core 2 has just been incredible. The 8800GTX just allowed ridiculous resolutions and AA.