I love that game. Everyone here knows GnG is a classic but no one knows about the Super Grafx version outside of the internet. This is my list of pros and cons for both versions.
Genesis:
+ Cheap
+ Better music
+ Diagonal controls
- Graphics aren't special
Super Grafx:
+ Graphics more true to the arcade version
- Music takes a hit
- Super expensive
- The system is expensive
- The system also has five games
Verdict: GENESIS