Things have improved a lot, like nuked sc55 but also Mame adding mu50/80. In short, this is very subjective... Though most games were accounting for the GM standard anf sounds used by the MT32. Overall XG was better, and so wtere those sounds, but we're for a different usecase and that is why they can sound slightly off. This is mostly that the games were dealing with the limits and quirky sounds of the mt32 and related period devices, like the sound canvas.

Personally I never liked most dos game soundtracks, as sample based sounds on the Amiga were overall better (unless they were Sierra games who sampled pretty bad mt32 sounds and blips and bleeps). I made music with the DB50XG over MIDI with my Amiga if I needed 'professional' sounding instruments. XG and a DR660 sounded better.