They really are a lovely machine, PAC. I forgot to mention but plugging everything into the back of the machine (even ethernet) makes a reassuring 'clunk'. Inserting a hard drive is laughably easy.
I had to break apart my RAID0 array last night because you can't install Boot Camp if the StartUp disk is raided - that sucked quite lot as the array was lightening.
Installing Windows at the moment and will be installing games thereafter should all go well, but I think I'm going to have to buy a Gaming box at some stage - I did want to split the 320gb drive and have XP and Vista each way, but Boot Camp won't allow that. I could install another drive but I want the last bay to be a backup drive that covers the other 3 drives - so it messes up my plans.
Regardless, the Mac Pro is a lovely machine and it will get my main usage of everything barring gaming - I just wish Apple would make Boot Camp a bit more gaming / high-end friendly. I inevitably didn't know about these limitations until it came to installing Windows last night, my own fault but I assumed it 'would just work'.
I will bench shortly when I get everything to how I like it - RAM arrived this morning so will install that also.