Even GOG has some oddities were the available copy is not the original experience. My recent experience of trying to play the original Mafia game. Booting it up a GoG copy, I found that there was no music while driving (a core memory of my original play through). This music has been removed... This also affected small radios you'd find playing music, they now dead.

It really took away from the game experience

I ended up scratching out my original CD copy of the game, installing version 1.0 of the game. It had all the music and better visuals

The patches removed visual features for performance, not GoG's fault here, not sure why GoG hosts an inferior version, its quite a downgrade. The music removal I do not understand.

(This all was particually obvious in an early mission, where you have to beat up some parked cars with baseball bats, the patched version show minimal dents and zero scratches, and the radio sitting in the corner make no sound. This completely changes in the V1.0 copy, so much more atmosphere)