ScummVM's Tandy sound used to be a complete and utter disaster "many years ago", sounding like a stadium organ reenacting the music in AGI. Nowadays, it's merely bad --- extremely aliased and with a ridiculous noise channel that sounds like a laser gun in AGI games (I just re-checked SQ2), wrong low frequencies in Zak McKracken's intro (but with a somewhat usable noise channel there, indicating that the Texas Instruments SN76489 chip was implemented several times, differently, for different game engines).
My biggest hatred of ScummVM however is due their endorsement and support of the god-damn awful James Woodcock remixes of Simon the Sorcerer's original MT-32 music. They're optional for desktop users, I suppose, but the only ones available when using the mobile versions, at least as far as I have been able to determine. A disgrace that most people now are only going to hear the game like this!