I'm using a iMac G5 and the only "problem" I've had is the "Lack of RAM" hang. Once I upped my RAM it's been great. The biggest problem is between the Keyboard and the chair.
Poser 5 on OS X makes it clear we mac users are the poor country cousins.
With the current tools at their disposal, it's sad to see the state of Poser on the Mac. It runs and feels like a poor port.
The Python Tkinter problem will resolve if Poser is properly migrated to MachO. It is due to development being stopped on the old OS 9 version of Tkinter.
I'm hopeful that with the current changes and "The Apple Renaissance" we will again see a concerted effort to modernise Poser. Fingers crossed X.