I think the SFFT driver requires SSE2, and a pentium III (or II) doesn't have it, so it's not really useful for vintage gaming imo. Or it could that it will not function along side nvidia drivers with a Geforce 4 installed into the AGP slot.
My whole reason for this setup was so I could swap displays and play either glide or directx games. I'm just happy the official driver works, and I think I will stick with that since I'm using it purely for glide and nothing else, I don't care if it supports directx 9 because I'm not playing any dx9 games, only older ones.
I would have chosen Windows98SE, but it's HD support is just too lacking for me, I have a lot of games, and the 120GB limit is just too small, I need that 2TB drive I put in there. It's also a lot faster than the older drives and not as noisy to boot.
Right now the system is stable and working good, so I am happy. I will try the 1.04 beta and see if the desktop resolution issue is fixed and just stick with that if so.