glock_nor_cal,
what jayflash said.
Imagine a laser. Now imagine it in a reflector. What's the reflector doing? You guessed it. Nothing. LED's can benefit from a reflector, especially DEEP reflectors and LARGE reflectors, but if size is an issue, an optic is a much better choice.
Incan filaments radiate in all directions at once, and thus are more suited to reflectors.
As for throw, LED's can throw a long way given the right setup. There's no reason they couldn't throw every bit as far as an incan.
In my opinion, it's the full-spectrum light of an incan which makes it throw farther, but I haven't really thought this one out, so take that with a grain of salt. Check out the thread "Why I still cary incans" or something like that in the Incandescent forum.