Apple :: Getting The Most Gaming Performance Out Of My Macbook Pro

I am pretty much deciding between keeping my macbook pro (in sig) and upgrading to an imac 24" with the ati 4850. With student discount it would cost me 1879 + tax. I just dont know if its worth it for me. Most all the pc games i own can be maxed on the pro,Save for world in conflict, crysis, and some others (about 5). My 360 gets most of my gaming time anyway. I just am thinking that it would be great to have the extra power in the 4850 for some of my current titles and having power for future titles would be nice. Also who couldnt use more speed for final cut express and such.

One game that annoys me on my macbook pro is Unreal 3. It is an amazingly graphical game. The new patch enables comprehesive settings adjustment. The thing that bothers me is that I can max it but fps drops by 65% on the water level. I want a card that wont have problems like this. Im not expecting wonders with the 4850, i would still use the modpacks for crysis, and run WiC in DX9.

However am i just missusing the macbook pro? What windows operating system runs smoothest on it? I have tried xp 32 bit and noticed some glitches with the led keyboard and such. Would 64 bit be the better option? Would upgrading the ram help at all? Im pretty convinced it wouldnt because as for vram i got double the ram compared to most people with the macbook pro, and still notice about the exact same performace. Also drivers? I never even touched or looked at the drivers? How do install drivers on a mac? Do i just go to nvidia's site on windows? If i erase the bootcamp partiiton will it delete the drivers? Will it conflict with leopard?