I installed an Interpower X5 HID unit in my 2000 model year Blackbird and have been very pleased with the result in light output. Yes they are brighter than ordinary Halogen bulbs, but I think the difference in colour is what gets you noticed in daylight ridng. The percentage of car drivers moving over or making room is definitely higher.
I joined up with a friend (Martin) who has a carb Blackbird a couple of years older than mine to buy a set of two units intended for car use. The price per unit was less than any single bulb kit we could find.
His were an easy fit as that bike has much more space behind the headlight unit. The ram air ducting on the injection type takes up a lot more space on my bike and I resorted to hanging the ballast/exciter from the bracket which supports the inner fairing trim panels.
Incidentally we decided not to use HID for the main beam/pass light, because HID's take a second or two to reach full brightness, the life of the bulb is also seriously shortened by frequent switching on and off.
We made no other changes to the electrics, retaining all the Honda plugs and wires so a switch back is possible, but very unlikely. The power consumption is lower at 35 watts compared to 55 for the H7 Halogen original, so all fuses are original too.
