I've noticed people complain about a lot of problems with iTunes on Windows that I just never see. In particular, people with much smaller libraries complaining about search and scroll performance problems. It strikes me that iTunes-on-Windows biggest problem is that it's frail.

FWIW: I've got iTunes running now; it's been up for about four hours, playing music and I did a sync of my iphone and ipad. It's bouncing between 45 and 55MB of memory [1].

[1] (library: 14,000 songs; 300 movies)