got the bulbs today, both the tektite ls407 and terralux tle-1s. I'm very happy about the output from both. I was looking for a replacement for my halogen bulb in my petzl duo belt 5 led, and the terralux tle-1s has slightly better output/adjustablility. I discovered this is partly due to the duo's reflector, since the ls407 is a side emitter instead of a lambertian style.
The light is NOT BLUE like ALL other LED headlamps, and that made me so very HAPPY
It is very close to natural light (like all other LED's claim to be but are no where close) I went out in the dark of night to shine it on my house (the tle-1s) and the colors are true with the tle-1s in comparison to the 5 led's in the duo (which appear to give off blue light) Best part = the center beam is adjustable. the 'hot spot' like with an apex is there when you want it and gone when you don't, its perfect harmony. I still need to test it underground but i'm sure I won't be disappointed.
I tried not to get my hopes too high because i figured a $20 LED replacement bulb woudn't be better than pretty much all other LED lights out there, but I've been pleasantly surprised. the ls407 is going to be put to use in an older headlamp with a fixed reflector that is a parbolic shape and thus provides a much better fixed beam pattern than the tle-1s did (in the same light) so i'm happy cause nothing went to waste. next step? buy two tle-1f's to put in my old princeton tec solo's and have 1w led headlamps for $20 (that still keep the princeton tec lifetime warranty and hopefully won't go dim in 2 hours - like with halogen/krypton)
In summary - totally worth it when a replacement halogen bulb is $5-$7 (and i blew up 2 last week) I took some pictures of the comparison of all three lights: halogen, tle-1s, and the ls407 (all in the duo with brand new batteries with full zoom in and full zoom out) but the camera is trash and i'll have to redo them (still cam in a video camera). Though I may still post the grainy pictures cause they give a decent idea of what it looks like anyway