I've had my u2 for a little while now, and maybe I'm slow, or just not familiar with this "donut hole" as the only thing I can see in my beam (when shining on a wall) is a little faint dark spot in the very center. When outside though, this is not seen...only the nice bright, crisp white (with very slightly and almost HID blue tint) can be seen. As far as imperfections, there are none visible while outside unless you are on the receiving end...especially if your eyes are adjusted for low light conditions before the blast. Even then you only see stars and spots but no donut holes. Seriously though, IMHO this is what really matters. Otherwise, to worry about something so simple then causes some to start fixing things that aren't actually broken, thus defeating the whole point of spending lots of money on something that is 1st grade quality merchandise. If there is a true defect I'd have thought surefire would take care of it. I only say this because I too am a person who is really picky and want only the best.