XP Pro 64 or Vista 64

[FeRaL]

I have the option of getting either or both for free though my school and would like to know which one is more mature.

[kenc51]

I have the option of getting either or both for free though my school and would like to know which one is more mature.

If you have the option to get both for free, why are you asking

32 bit is more mature and stable IMHO, but 64 bit has come a long way!
If I was you, I'd have XP and both vista versions installed, that way you have the best of all worlds.

[Zelig]

Vista 64 bit all the way, it's a better OS, with better compatibility. I can think of almost no reasons for anyone to be using XP Pro x64.

[Major_A]

Even though XP Pro x64 has 2+ years on Vista x64 it has less support. I am running my HTPC on XP Pro x64 and every driver, minus my video card is old as hell. It runs fine and I haven't had any problems with it but you might as well get Vista.