vulchor: I'm afraid your memory is not very good when it comes to the way MIDI sounded on your SB16 back in the day. The SoundBlaster 16 had its own MIDI chip that had much better instrumentation than MGSW, the default MIDI synth in Windows.
[EDIT]
Here's a comparison between the SB16 (which was ok quality for back in the day, but not quite as good as Roland or Gravis) and Microsoft GS Wavetable.
https://www.youtube.com/watch?v=HXkUK4ufWfI Solarnova: Hah, I said "somewhat resembles my SoundBlaster 16" not 'resembles my SoundBlaster 16 exactly.'
I found out a long time ago that Music and Audio for this game is highly subjective. Anyone playing this in the DOS days with a different sound card than another player had almost an entirely different experience.
There isn't one version actually better than the other, because it's highly subjective and highly opinionated. All I know is that my SoundBlaster 16 sounded great and that was the ultimate experience for me.
(I also keep in mind that most of the developers used an SB16 when creating the game, it was only a 2 year old card at that point and by far the most popular audio card on PC-DOS.) :)
For sure it is subjective, and that was really the biggest downside to MIDI (although I think of it as an upside because you can choose your instruments, but devs weren't able to give the same experience to everyone).
However, we should all agree that the default Windows MIDI wavetables are awful. There are instruments and effects missing, and it is only Mono. For those reasons alone are enough to criticize GOG for including FLAC and MP3 downloads done with Windows GM. They offered the MIDI files themselves which was a fantastic idea, therefore making the other formats redundant.
Including FLAC and/or MP3 downloads of the soundtrack would certainly have been valid had they used original hardware or even good emulated soundfonts.