I've used a Mity Max. Bike was harder to start. Lights are dim at idle. Works better if idle is raised a couple hundred RPM. Nice features it eliminates rectifier,zener, and batt. thus no battery acid.
Mity Max boxes are no longer manufactured. Be aware of used ones, they did not hold up too well over time.
Both Podtronics and Typanum make a similar unit in much smaller packages than the old Mity Max (looks like a guitar effects pedal). The only other thing you might want to include is a capacitor in-line. Get the type of Capacitor as used on Norton Commandos (also order the Norton capacitor holder) or a solid state unit at radio shack of the same Farads as the Norton one.