I just ordered my mac last night (white 2.0GHz Intel Core 2 Duo, 1GB memory, 80GB hard drive, Double-layer SuperDrive) and I want to put halo on it. I know there is a mac version, but I also ordered parallels software. As the PC version of Halo is $10 cheaper, I was wondering if buying halo (pc) and running in parallels would be slower than just buying the mac version. thanks!