i did this mod too, mounted mine on the fender bolt as well in the little valley. w/ the 25 watters, they are pretty bright. brighter than stock for sure. i've got mine wired to run as low beams and kept the stock light's hi beam. visibility is def increased except for the fact that because they're mounted in that little valley, the far peripheral is truncated.
also, another thing i did (maybe i'll start a thread on it) is wired in a killswitch for the tail light. so that whenever i'm running the tail of the pack and don't need a brake light for anybody behind me, i'll kill the tail light so that the headlights don't dim when i hit the brakes.
also will come in handy if we ever get chased by rangers or patrol (we trespass) cuz it's a lot harder to see where someone you're chasing is goin if you can't see their tail light.