The teeth on the bezel can tweak the beam a little. My 6PDL has a pentagon shaped beam. I kinda like it. I have a KL1 on an E1e that throws a square beam. Took me a little while to get used to it.
My E2DL has a slight artifact caused by the teeth but it's only noticable on white walls. In real use you don't see it.
Does it really matter? I see tonnes of posts like this and for the life of me I don't understand them, 3 foot white-wall photo's, etc. To me, that is like patterning a shotgun at 2 feet. Maybe I just don't get it
I dont think it needs to be, as long as it resembles a circle. I dont mind oval beams and such. i actually like the beam on the surefire M3 i bummed off of a non-flashohalic. (my step-father who learned about surefire from me and used the company credit card) it looked like a zero that was a bit sharper at the edges for those who dont know.