While I don't have any personal experience, with HID retrofit kits, two co-workers, one with a Honda 'Leadwing', and the other with a late model Victory bike, installed the single wattage type HID kit, and weren't happy with the results .
The kit that Justin installed, has a movable reflector on the bulb, so when high or low beam is selected, it moves, and supposedly improves the light pattern .
You may want to consider installing a relay kit for the headlight .
http://www.easternbeaver.com/From what I've read, the voltage drop in a stock headlight circuit, is enough to cause a significant reduction in headlight performance .