I haven't used Vista at all, but I've seen and heard things about it. I had XP Pro before, (new computer now and my dad hasn't installed XP and I can't find the disc and don't know how to set it up) and I know it's good. If you like Vista then you should get it. And if you can't get your XP laptop fixed, then maybe get XP on your computer if you can't install that program or whatever.
The US-122? It's a recording interface... I downloaded the drivers from a website, was that close to having it installed, when a popup appeared saying "Cannot install on this version of Windows." I was pissed >_<
And anyone else who says Vista is buggy, well, yeah, a little bit, but not so much. But there are some compatibility issues, like with my interface. I don't even know if the Cubase LE program that came with it will install on Vista. I'm thinking about dual-booting XP on my other hard drive (my new comp has two hard drives, each 125GB each ^_^ )
And I hear SP1 is coming out soon.