The Gimp is far from being professional-grade software. Really, I've tried using it, and everything just feels so restrictive when compared to any version of Photoshop that's been released in the past eight years. I love Paint.NET, but it, too, is still just feels too restrictive in comparison to Photoshop.
Anyway, I'm on PC's side. Really, most things Mac-related just make me want to punch someone in the throat. The damn things are really no different from PC's, aside from the fact that Apple has so much control over the actual hardware aspect of things that the machines are certainly more reliable from a software stability standpoint. Still, Windows' reliability and stability certainly isn't anything to scoff at. I blame third-party software vendors, personally, as Vista support is pretty much inferior to that of XP, with most developers just throwing together unoptimized garbage and hoping for the best. Plus, despite 64-bit Vista being very solid, device drivers from major companies such as NVIDIA are just horse shit, and 64-bit versions of certain software is just completely missing. (Really, Adobe, getting your fucking heads out of your asses.)
Even the game performance in Vista is disappointing. Still, I use XP, and I've never found myself unable to find the software that I need for it, whether it be for image/sound/video editing or gaming, among other things. Macs (and Apple in generally) really just garner too much praise. Yeah, of course it's more stable. Apple has complete control over the hardware side of things that it's just sick. The only thing keeping Mac OS from running on anything other than Macs is Apple's insistence on keeping it that way. Mac reliability and stability would turn to complete shit if it supported even a quarter of the hardware that Windows does.