The other think you may want to consider is HID usage in the halogen reflector housing on trails. The light is scattered and will cause glare for oncoming traffic. Personally I would like to put projectors on my sled, however the cutoff could be a problem with low beam on the trails (I'm in MI). For this I would like a handlebar mounted hi/lo switch on my SBA. Some people don't care about this though. The other argument is that on/off throttle and brakes would quickly change the headlight aiming anyways...
HID's were just not mean for halogen housings, there are plenty of HID fail shots on the net. I ran drop in HID's in my truck, although scattered, the light output over stock was great but I got sick of getting brighted. Projectors are they way to go.