Unfortunately the game froze while starting. I checked the tech support forum and saw several other people with similar problems but no helpful advice (other than 'reset your preferences' which made the problem worse.) So, I guess that's $20 I won't be spending.
How hard is it to make sure that your game can get through its world-construction phase without failing? If you can't make a progress bar work, why should I believe the rest of your game is any good?
Later: Also tried out the demo of Avernum V. It tried setting the display resolution to something my TV doesn't support, which was a pain in the ass. (Note to developers: make full-screen the option, not the default. Although this game can't run windowed anyway.) I managed to get into the correct menu to change it using VNC but I'm not thrilled so far.