Thomas,
The big difference is weather the coil is configured 2 wire or 3 wire. The motorcycle coils are configured 2 wire. That means the coils are conventional, with the trigger happening remotely just like an old points system. The 3 wire coils have a local trigger system using a 5 volt trigger circuit. The motorcycle system has a simpler coil, the trigger system has a simpler ems box. I don't know which has proven more reliable. Bill