This is just the info I was really looking for! When I decide to drop the money on upgrading my headlights, I know exactly where I will be going!For the retrofit kit, the "North American" kit has smaller projectors than the Mini H1. The north american housings use a 9007 bulb and the opening in the reflector is smaller. Additionally, there is a protrusion from that opening about a quarter of an inch out from the surface of the reflector. What that means is that the larger Mini H1 will not fit into the housing in a "bolt on" application. It sticks out too far and the front headlight lens can't be put back on. That is in contrast to the European housings which use an H4 bulb that has a larger opening. The larger opening and lack of protrusion means the projector can sit back further and there is just enough room to bolt in the Mini H1 projector. If you wanted the larger projector in the North American housing you'd have to use a dremmel and cut yourself out a larger hole. But by doing so you'd also be cutting out the bolt mount surface and you'd have to epoxy the projector in place. In other words, it gets pretty messy fast, and very difficult to do well. Also very time consuming. For that reason, we offer the smaller projectors which are an easy bolt in option.
In terms of the projectors, the two will give you different output due to the different lens sizes (2.5" vs 1.8"). In essence, with the larger projectors you end up with the light spread more to the sides of the road, with the smaller you end up with more light in the center.
Anything should have better output than my stock DOT buckets really.