RE: g5 optix sight
The sight is top notch. Get the .19 version.
However, if you are ham fisted like me the one thing you will wnat to do is go to your local hardwear store and buy 3 of the smallest lock washers they sell and put them under the lock down screws for the top 3 pins. I broke off one of the tiny screws and I've found that this will fix the problem for about $.40.