The Duke Nukem 3D theme composed specifically for the Roland GS extensions sounds incredible on a SC-88 when compared with the normal GM version. I found out today that there are some Yamaha synthesizers which support these GS extensions, and it would be interesting to see how it compares with the Roland samples.
Yamaha's GS map sounds excellent, but compatibilty level is 55mk2. Only Roland modules support 88 native modes. Just like later Roland modules only support XG Lite (XG Level 1) (MU-80).
If you want to hear a Yamaha MU2000 in GS mode, I have recorded lots of X68000 games on Youtube.
Modules: CM-64, CM-500, SC-55MkII, SC-88 Pro, SY22, TG100, MU2000EX, PLG100-SG, PLG150-DR, PLG150-AN, SG01k, NS5R, GZ-50M, SN-U110-07, SN-U110-10, Pocket Studio 5, DreamBlaster S2, X2, McFly, E-Wave, QWave, CrystalBlaster C2, Yucatan FX, BeepBlaster
