Those are interesting points; I've already got the Luxeon ordered and it's on its way. I am concerned about heat-sinking it; I'm going to experiment with that.
Originally Posted by jeff-o
Don't discount the 3W bulbs completely, I found that using two 3W LEDs was actually a better solution than a single 5W LED. This is mostly because a 5W LED was more than twice as expensive as a single 3W, which meant I could implement a dual-beam 6W headlight for less than a single 5W. Also remember that the 5W LED will get much hotter than a 3W, so you'll need at least 60% more square inches of heatsink.