Been running Leopard 10.5.3 for almost a week. I'm dual booting WinXP/OSx86. I've completely switched over, using OSX for most tasks and keeping XP for occasional gaming. Even bought a Apple keyboard, my old one was on the way out anyways, kept my Razor Deathadder though, especially since they built drivers for it.
Got a ton of applications already installed, just loving it