I haven't saved the answers, but the LED vendors I contacted were clear that the light output of even their strongest multiLED towers could not match what stock lights in good reflectors put out. It has something to do with direction and beam angle. Manufacturers like Rizoma try to use the most powerful single LED they can build into an affordable housing without too much added electronics and spread the light through a lens.
My impression of LED lights is that they are sharp and appear very bright in dark places, but not in day light or from a distance. Like a camera flash, yes, it's bright, but is hard to tell where it came from. Maybe torque vs horse power is a suitable picture...
I think it's all about what a regular reflector does - directing all light in the intended direction(s) - LED is extremely bright in one direction, but when the output is spread, it's spread too thin.
My interpretation, anyway
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