I purchased one for my version 3.0 G-32 last year. It sits in a box in my nightstand drawer.
The reason I do not use it anymore is that it requires too much maintenance. It was pretty cool at first. It really does work and is accurate. The problem is that the batteries only last for maybe two range trips and the guide rod spring needs to be replaced maybe every third trip.
I was experiencing failure of my pistol to return to battery because of the weakened spring.
If you are diligent in maintaining this add-on then go for it. For me, I just did not feel that the effort was worth it. I feel confident in my ability to hit targets even in a stressful situation without the aid of the laser and I am not thrilled with being in a situation where my gun does not operate as expected.
For me this was an add-on that was a waste of money.
Your mileage may vary.

thanks for the advice. the spring only lasts a few hundred rounds? wow