Okay, I've dug a little deeper into the archives of this BBS, and did manage to find a couple of posts pertaining to GEM.

I know if I ever replace it, I'll be going with the X1 or possibly PSR9000. It would've helped to purchase it from someone that knew what they were talking about. Nonetheless, I still think the SK880 sounds great. The OS could be a littel friendlier.

I saw a thread regarding General MIDI file compatibility with a GEM. I myself, did not purchase the board to be a glorified karaoke machine, but I have messed around with enough MIDIs to notice a few quirks. The 'sound' difference of the same file played between instruments I believe is related to GEMs OS displacing sounds in its banks. If I'm playing around with different samples and 'peformance' settings, MIDIs often have at least a single 'voice' that is out of place. I get around this by setting everything to default(clearing memory). This is done in the 'General' control section. On the SK880, the same thing can be accomplished by turning the tempo dial while powering on.