I have one for my G23, does that count?
I like it. While I'm not sure if I were to use it in a combat situation, it is a blast at the range. It's fairly accurate, and is very impressive. You also don't need to limit yourself to special holsters. Finally, it is fairly easy to install with the step by step video.
My only complaint is that sometimes if I'm shooting with it off, it will flip itself on automatically.
One more thing, I had a problem with it and called LaserMax for a replacement. Their customer service was excellent, and they shipped the piece out immediately, free of charge.