They are working on a mac friendly verison of Adobe Audition :) I'm not sure what the requirements are but here's a link for more information:
Also here is a great tweaking article from Sweetwater Sound for Vista and they have one for Windows 7. Obviously travel with care here. I optimized my pc for audio and that's all it is used for. It isn't even connected to the internet except for updates that i hand pick and some software loads.
As far as the pc/mac debate. . .you can tweak all the live long day on a pc (great for people who like to adjust and problem solve a lot.) I do some, but not in the middle of a large project. Mac seems to be a "crank it up and go" and it does what it was designed to do usually without fail for a long time.