Mike101,
     I've had both OS's on my system for quite a while, but was using 98 for its compatibility with all my hardware.  Not until recently did I start using 2000, and it is SO much better!  I have 320 MB RAM, and 98 doesn't seem to use very much of it.  In 98, my cursor won't move when web pages load (cable modem), but in 2000 I don't have that problem.  And, web pages load much faster.  Overall it's much smoother and feels much faster.
     However, I do have compatibility problems.  My Turtle Beach Montego II sound card isn't fully compatible, so I don't have bass/treble controls.  My STB Velocity 4400 TNT1 video card doesn't play games well.  Madden 2K is noticably jerky - so much so that I play it in 98.  I can't get my Kodak 240 to connect via USB, so I load pictures in 98 too.
     But, I do those things very rarely, and would rather just take the additional 2 minutes to boot over to 98 when I need to do those.  I will be upgrading my sound card soon, and perhaps video too.  But for everyday computing (web, office, email), I run 2000.
Rob