I was wondering if this is fixed? I played a little today and didnt notice any issues regarding speed. Met some enemies on a planet and they moved at a slowly pace. I never played this back in the 80s so I dont now how the game should perform. But it seems fine to me.

The speed issues back then were where changing the turbo from 4.77 Mhz to 7.16 Mhz. Just kidding, but it was as smooth as a corduroy road back then too. If I remember right, mostly they happened because it is procedurally calculating the map as you pass the sectors... and then enemies depend on the aggression and speed they have. If you stand still, it drops into the loop for the enemy more often and suddenly, they move really fast. Every instruction pulse was precious back then. The dosbox controlled one seems smoother, and almost too fast some times, like when you stand still.