My friend measured the power draw of the EL500 with the regulator in the circuit (it is a regulator, by the way). He said about 1.3 watts.

As far as comparisons go, there is another thread with reference to charts that compare halogen to other lights over large power ranges.

As far as real life testing goes, the EL500 is, as best as I could determine by eye, exactly as bright as a 2.4watt (4.8v .5amp) halogen bulb in a cheap headlamp I've got. That's comparing the EL500 fully assembled, with its reflector, etc., with a 2.4watt halogen bulb with its reflector housing, etc. By exactly as bright, I mean that each light exposed details of objects, text at some distance from the spot, etc., as well as the other, to the ability of my eyes and brain to discriminate. There is some give here, I suppose, since the LED has much whiter light than the halogen bulb, and that might make a difference, one way or the other, under other conditions than in my completely dark hallway.

The EL had brand new batteries, but the halogen light was probably some time into its battery life. Perhaps the halogen would have a slight edge with completely new batteries.

The EL is a good choice compared to low power (4AA) halogen lights, in that you get significantly more run time per battery set. I don't think the EL's quite bright enough to use as something other than a be-seen light, or an emergency light, but some people (in this thread) say they see fine with it. I think it's a matter of how much guesswork you're willing to tolerate with a headlamp. At any rate, I think given what's actually available in cheap, low power halogen bulbs, the EL500 puts out more light than an equivalently powered halogen set up.

I don't think you were communicating with a real engineer. I think that reply is from some customer service rep, or repair guy, or something.