Dear Michael
Here are my finding on my system to help you:
System = PIII 1Ghz Win 2K
1)Graphics performance enhanced from 32 FPS – 38FPS
2) In direct X mode mouse is still viable after leaving windows mode.
3) In Direct X mode F12 for menus flashes the menus then they disappear instantly.
4) Starting the program in Windows mode, the sound is at full (or default) for some time or indefinitely. Switching to Direct X mode the sound drops to the stored level.
I hope this helps