I back what Dartholomew said 100%. Very well summed up. I approached this with NO prior retrofitting skills (or baking for that matter.. I'm yet to do my first muffin), and while it was long, I didnt screw anything up or break anything. It did take me the whole weekend though, so stack on food, beer and tools if it's your only car.
Illumination - good point about the width. Halogen lights tend to have a very significant frontal hotspot which gives the illusion of a distant reach. These HIds dont reach further, and they don't illuminate much more at that particular spot in front. However, the overall illumination is a MASSIVE improvement over halogens, especially to the distant far right side. Personally, this is what I need for deers or in a forest - not a laser spot in front.
Aiming: it is a total biatch. To get the hotspots where they should be, the position of the bulb with respect to the projector has to be changed. I used a spacer, made out of a little piece of wire, put on the top right bulb support "pillar".Additionally, I didn't screw the retaining ring very tight, and I wrapped a tie-wrap around the back og th bulb, which I pulled out of the headlight, and attached to a screw. Very ghetto - but one should keep in mind that even without doing any of it, the results are far from bad. The hotspots are not that massively brighter than the rest of the beam. I'll email TRS asking if they can figure and sell a spacer ring which would improve the hotspot issue.
High beam illumination: simply fabulous. With the bixenons and HIR halogen high beams, it's a flood of uniform, far reaching light.