The good: It should be about 10% faster .. sometimes more, sometimes less, depending what the game is up to. (GEM Desktop went up 10fps, while most games go up by say 5fps.. but it depends)
The bad: It seams to have a problem loading Xenon 2 and crashes; it can play xenon 2, so load it up in 0.8.0 and drop a savestate, and then load the savestate into 0.9.0 to play it I'm not sure if the problem effects other games or just that one.
The gooder: In theory, using the new toolsets should make life easier for some updates I'd like to do... better audio, some Tapwave enhancements, etc. Certainly means I can build it in my normal development environment, which is handy
Source : zodiacgamer.com