I like XP Pro and 2000 Pro and I have 6 hard drives all 7200 7.6 seek Seagate's 10 gig all ghosted 3 with 2000 Pro and 3 with XP Pro. I will have to say from my personal experience 2000 Pro man it's fast! I have Photoshop and it's definitely opens it faster than XP Pro. To me 2000 Pro is just more responsive than XP Pro. XP Pro did speed up a little after I went in and tweaked it out and got rid of all the bells and whistles but still not as fast as 2000 Pro on my system. But bottom line I like them both.