I've noticed a few glitches on startup or sometimes if you tweak a setting with charts, but if you close and reopen them they're usually fine. Some of the mouse-over fields don't pop up either. Minor annoyances compared to Windows/Linux, but not quite as good. I also suggest rebooting if you install one of the frequent java updates. I've had TWS get super slow and eventually lock up the system otherwise. Better to reboot on your schedule and not at some bad time. I'm running an older build of TWS, new ones may have addressed some of these issues.
Yep, I had some problems starting the trader and had to reinstall JAVA. Potentially this was caused bij de 20 October update of JAVA. I didn't work with the Mac since, I'm not sure if OSX was the problem.