i went to a local mac user group, when i bought my first mac a couple of years ago. bit of a mistake that.
they were all mental.
having said that, most of the folk in my department at work, constantly drone on about how fast their pc is, who's machine has the highest fps, which machine has the best built in fishtank etc.
i use my mac because i like the OS and for most of the stuff i do, i find it easier to work with. If Vista is easier for me, i'll move to that.
but, i also use a pc because i used to be a design engineer, and all my CAD software is PC only. its a decent machine, and i thought it would be pointless spending thousands trying to find mac alternatives (if solidworks is ever released for mac).
only problems i've had with xp, have generally been when i've been pissing about with it(trying to get my archaic tv card to work).
i'll work with whatever is easiest for me, and at the end of the day, its pointless getting worked up about it, it's just a box with fucking bits in it.