I'll just limp home with my X2 6400 that I bought at the height of AMD's market reign (i.e. 2 weeks before Intel released the Core2 architecture.... self-abusers).
To be honest, I'm slowly coming around to Vista - I knew I would eventually. I just wish MS would take a bit more time to polish things off before releasing stuff with so many obvious problems. I'm also aware of the restrictions in place on XP with all the new CPU architecture out there, but I need an OS thats guaranteed to work, and XP fits the bill perfectly.
It might be time to switch soon anyway for me, since DX10 games are starting to come out by the lorry load!
AMD were always good at integer benchmarks, and older games, due to excellent integer horsepower.
Real world, Athlons seemed slower than P4, due to poor clock rate (the numbering std was comparing integer performance). Athlon64 didn't offer anything at the time. Even now, XP64 is a bitch.
Vista is pretty solid - I haven't had (non driver) crashes since pre betas. Its not as mature as XP, and developers are only now truely getting to grips with it.
Yes, its hardware requirements are higher, but its 6yrs newer!
For a laugh, a few months ago, I installed Win3 on a vm on the OOF server - from point of DOS starting to load, and Program Manager ready was less than 3s

- not that I condone running such old shite