I have just upgraded to vers. 8.0. I have a G3 iMac running OS X and made the switch as soon as it came out. Updating my main file was seamless and the program runs very well. The main advantage is that I do not have to run classic mode (OS 9) any more. The program takes advantage of the OS X dialog box structure making entering data and finding files easier. The only quibble I have is that the program always opens up in the program folder instead of the Documents folder where I keep my file (backup is easier if all documents are in the same place). There is probably a better work-around, but I just keep an alias in the program folder and that takes me where I want to be.
If you are thinking of upgrading, go ahead, particularly if you have OS X installed. It's nice to see a Mac program that works so well and is still supported (take that, UFT).
Note: there is a minor bug fix available on the web site. It is easy to download and install. I received the notification when I registered.
(Just to let you know: I am not affiliated in any way with Leister Productions; just a satisfied user.)