I ended up with a copy of Vista Business edition through Microsoft's power together program, and first installed it on a separate partition and kept XP. I haven't gone back to XP since, however, Vista just works for me fine, I have no driver issues, or really any, other than the iTunes issues before they issued the latest release.
However, when I first installed Vista, I only had 1 GB of RAM in my PC, and my computer would frequently lock up and get overwhelmed when trying to run both iTunes and Photoshop at the same time, due to it using too much memory (Vista itself was using between 45-55% of memory consistently with no programs open). I upgraded to 3 GB of RAM later (only cost $75) and now I run InDesign, Illustrator, Photoshop, Bridge, and iTunes all at the same time with no slowdown, and only about 60% memory usage.
The things I thing Vista is worth it for are, well first of all the new search engine. It works PERFECTLY. The interface is much nicer looking than XP ever did, and the organization features in explorer are perfect for photos, music, and honestly just about anything.
Unfortunately as far as gaming though, I can't really say much, as I don't have a good graphics card, and I don't game on this PC at all. I have however, had to work on a laptop that a person had purchased with Vista, with an external graphics card (I think it was the GeForce GO 7600) and 1 GB RAM, and when running games such as Combat Flight Simulator 3 and Flight Simulator 2004, there was noticeable lag and slowdown. Eventually what we ended up doing was reformatting the PC and installing XP, and the games ran noticeably better. So it does seem like there are issues with gaming in Vista, but the low amount of RAM could have been part of the problem.
Intel Pentium D 840 3.2 GHz dualcore
3 GB DDR2 667 MHz RAM
160 GB SATA HDD (w/Vista Business)
120 GB SATA HDD (w/XP)
Nvidia GeForce 6200 LE)