I've had LG405s on one of my J-Frames since September 2016. No issues from my end, to include 100 rounds of Gold Dot 135gr+P and somewhere around 1K mixed factory loads and reloads.
I will say that I'm not enamored with the shape and size of the grips. I'd really prefer them to be a bit wider/have more of a palm swell, and they seem to be more of a straight grip than, say, the Uncle Mike's Speigel clones. Don't get me wrong: I can make them work, and do because I really like the capability they provide, but they could be a bit better shaped. I don't perceive any reduction in recoil/increase in shootability due to the rubber air gap thing on the backstrap.