bluebeat1313
JonD can you please explain "you won't find them in a GM module." part... I am a bit confused here. My understanding is, regardless of GM rules your synth will sound as good as your samples are (for the most part). I do not believe the software on your list is fully GM compatible. If I remember correctly, none of them have GM bank chage option.
My only point was that GM-modules (sound canvas and the like) can't compare in quality and realism with the better-sounding romplers like Halion Sonic, etc. Some romplers do allow for bank customizing and mapping for GM/live performance. For example, I believe Halion Sonic can do it fairly easily, while Sampletank and Korg M1 both offer a GM soundset.
That said, you are correct -- generally speaking romplers are no direct substitute for GM modules if you need the GM format. Also, while I think it's probably too cost-prohibitive to improve the TTS-1 soundsets, I think your idea about allowing user sfz/sf2 banks would be the next best thing. That, with a few needed fixes and graphic tweaks and I'd be happy with it (TTS-2?).