The guy who's job I took over in Afghanistan passed off a set to me. The grips were on their 4th or 5th year of downrange use and they showed their age with some nicks in the rubber and the checkering having been worn smooth in places where gripped. I threw in a new set of batteries last October and they were still going strong when I took them off a couple days ago to hand off to my replacement. These were for an M9. Observations follow:
Pros:
-They absolutely work in low-light situations where the front sight cannot be easily acquired. Yeah, you have to know your target and what's beyond it, but if I see the outline of a man with a rag on his head and AK in his hand coming over the wire, that's probably not Joe Snuffy coming over to borrow my 1151.
-Batteries still G2G after 10 months of use. I'm a fobbit most of the time, so "use" included a couple dozen missions, monthly range trips, helicopter rides, snow, rain, heat, dust, and multiple dives into the dirt for incoming.
-Mine rode in a SERPA while on the FOB and a Safariland drop leg while OTW. Mine where a slightly older generation with finger groves. The rubber texturing and the finger groves fit okay and did not interfere at all with other operations of the pistol.
-I never found myself becoming absolutely dependant on on the laser. YMMV.
-If they fail, laser grips don't break down. They just become grips.
-Used a couple times in escalation of force situations with good results.
Cons:
-Not visible in bright light. This is just a light neg against the product IMO; front sight is fine for this most of the time. I turned the switch on when going on mission or when the sun was going down. Kept them off if I was outside most of the day. I suspect the batteries would last quite a while this way.
-The hex screw to adjust the sights wasn't commonly available (not going to be an issue for most users, as it comes new in the packaging). POI was 6 inches low for me at 25m.
-I didn't have this problem with the M9 model, but some others that I've tried holding have resulted in my indexed trigger fingering covering the port where the laser comes out.
Overall opinion: Nice to have, but not an absolute necessity. The grips have great potential to help, and used/maintained/trained with properly they can't hurt. If you become dependant on them and they fail at a critical moment, that's on you and not the grips (see my sig line). Not going to pay 250USD for a pair of my own, but if I find a good deal on a pair that fit my carry gun I'd probably bite.