To be honest, I'm a poor one to ask. It's great if you like 'Roland' sounds. For GM sounds, it's probably the best in it's class. Just as an experiment, I've played SMF's on the SonicCell and Fantom G for comparison. The SonicCell sounds better IMO but I'm not sure that's a fair comparison. It certainly HANDLES SMF playing better than the Fantom (or anything else). I like different boards for different things but I'll usually just grab whatever's handy and use that. I'm usually going for El. Pianos (prefer Triton) and guitars (like the Yammy's). Just a personal thing but I sort of view Roland sounds as good all around but great at nothing. If I had only one sound source, it would probably be a Roland. If I were really being picky about a sound in the studio, it would probably be something other than a Roland.

Not familiar with the SRX cards but I would describe the on-board acoustic sounds as "mostly okay". Of course, you get a lot more with the SonicCell than just the sound-set, so that's something to consider as well.

Probably not much help but the truth is, I can't think of anything better as a general purpose sound module (with additional usable features).

chas