Currently, with LEDs you basically have a choice of throw or flood. My E1L/E2L out-throws a regular E1e/E2e (though has little flood). While the KL4 on an E2e body (L4) has slightly less throw then a regular E1e, but has more flood then my E2e.

That is why I like Surefires interchangability though. I can carry an E2L or L4 for everyday tasks where I want extended runtime and to not have to worry about bulbs, or I can switch to a regular E2e just by changing the head and bulb if I want. The same can be done with the 6P/G2/C2/ect.

Anyway, I'm sure for the average person LEDs will all but replace incans in a few years.