I reinstalled Leopard today since my OS had become slow and sluggish, xcode wasn’t installing correctly and this install was kinda dodgy (it had been upgraded, backed up with time machine and restored twice, and been trashed). I’ve cut down on the ammount of silly applications I have, and have just restored the ones I need. The general install was nice and I done it in less than a night, including all the restoring and that.
What I really liked about the reinstall is that OS X makes it so easy to restore stuff. All the main data is kept nicly orangised in folders that are easily accessible, unlike Windows. I’m only restoring the data I need, rather than everything so that has been a big bonus.