The only thing that bothers me a little bit is the lack of third-party support, but that may be a blessing in disguise (no viruses and less distractions). I'm also not too fond of the Finder, and using Firefox on Windows has ruined my enjoyment of Safari somewhat, though I think it's a great RSS-reader. Networking between Mac and Windows.. well, I'm no expert but it works fine 80% of the time (On some machines I have problems).
For the rest, I've only been a Mac-user for a little over 13 months now, but I'm here to stay!
For the rest, I've only been a Mac-user for a little over 13 months now, but I'm here to stay!