I'm giving this game a gold medal, I've been playing it extensively and it's working better than on windows (more stable).
*However, not everything works. Intro videos don't play. Ghosts and some effects show up as transparent or multicolored effects instead of translucent.
In the Ancaria campaign these are not big problems (so far) since the enemy ghosts I've encountered so far have rendered correctly and when there is a translucent effect on the character it just doesn't look as pretty.
The game plays better on windowed mode since it has a hard-fast resolution.
And since I have the steam version the bottle already has all the fonts and directx installation that the game may otherwise need. If you have the gog.com version (or the cd version) I recommend you install it into a steam bottle.
I don't miss the videos and haven't encountered a game problem with the translucent effects. I've played maybe a 20% of the story and no issues.