There are just a few thiings that are really important:
1. Workbench - true to the original spirit (Windomanager and Filesystembrowser with the classic feel)
2. Old Amiga Software works (preferably OCS stuff too, but thats optional)
3. Runs on real Hardware that you can order and buy new with a warranty.
4. No bloat - not booting into one OS starting virtualization booting the 2nd one and than doning emulation ... just keep it clean and simple ...
5. Hacks are only there to bring you tommorows features today - they are not a design concept!
6. Browser of at least OWB 3.30 stability, compatibility and performance.