Both PC Magazine and Maximum PC highly recommend against upgrading. Finding drivers that work is nearly impossible in some cases. One article said some versions of XP require specific versions of VISTA to upgrade. Wrong version = wasted, unreturnable purchase.
If you are going to upgrade, get the full version. With an upgrade version, save your XP disk. If you ever have to reinstall, the Vista upgrade requires XP be re-installed first, then the upgrade. Got a little time on your hands?
A software salesman told me the new PCs have Vista versions built specifically around those PCs. Some audio drivers just don't exist yet. NVidia and ATI are having trouble getting their drivers to work correctly. I recommend waiting 6 months.
Yep, I actually put that into my post. Also you dont need to even have an OS on your PC to use the upgrade, there is a simple work around. When installing and it asks for your old cd key, ignore it and continue it will continue to install. After its done installing you reboot and do a reinstall and then put in you cd key for your Vista. IIts a little more involved than that but thats essentially what to do.
HEres a more in depth article on it.
http://www.winsupersite.com/showcase/winvista_upgrade_clean.asp
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus