Word of caution on the LEDengin's. I couldn't find any binning info listed for the LEDengin offerings on the Mouser website. My guess would be that they are selling the lowest bin. The 660nms, I received seem to bear this out.

I would only use their 660nm since they are the only game in town. For everything else no reason not to consider Luxeons, especially since they are cheaper and you can hand solder the bare emitters.

I am also wondering how much better penetration you get with multi-die LEDs compared to singe die. What is better using 3 single die leds at 2 watts or a triple die LED at 6 watts?