Full Review

I have used XP and vista and if you ask me which ones better i would say XP is way better.
It runs with minimal startup memory and performs really well. I havent had any computer crashes while using XP.
The other cool thing about using XP is it automatically downloads the required updates from the microsoft website.
You can customize XP according to your needs and get rid of unwanted programs and applications that run in the background. You can give it a 98 look but still make it perform as XP.
As a developer you dont want your system to lag because of some annoying graphics and unwanted applications that hog up the system memory. And XP lets you tweak it exactly the way you want it.