You won't see much of a difference, between the two processors. And get the 8800GTS 320mb instead. The 640mb provides no significant advantage over the 320mb. Double the memory, does not mean double the performance.
Grrr wish you gusy would have convinced me that! Otherwise i was just gonna get the GTX instead of this stupid 640MB Card!
Edit: Do you think I can RMA this to newegg and order the 8800 GTX instead? Like I mean RMA and say its not working anymore, it has 1 year return policy thing and they'll give me a new one but can i request to get a GTX instead of the same one? I might give them a call