If you like the MU100 drums for stage use, do yourself a favor and install a PLG150-DR. It's quite the significant upgrade.
Regarding Roland, they sound totally different and both have their strengths. This forum is mostly focused on PC games, and since the SC55 was often used to make game music on, it tends to be favored here as it's how the composer would have heard it. I enjoy both companies, but I find a lot of people will favor whatever module they owned first as it's what their ears expect.
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