I got sick of the vista bootloader. I run MCE 2005 90% of the time. yet if I restart the computer and leave, it will boot to vista.
I installed vista with all of the other Hdd Disconnected. you can go this route after an xp install. now connect those drives back up
now if I want vista, I either set the bios to boot to the other hdd (for a continuous boot) or I hit esc to get a boot menu (for a temporary boot)
your documents won't have a problem with this