What is it? and what do you like and dislike about it.

LaserMax guiderod laser on my G43X and am liking it. Its my first Glock LaserMax but I have had them on my Sigs since they first came out or I discovered them in the early 90's.

Despite what the naysayers spew I have never had a failure of any kind.

While I prefer the on/off switch on the Sigs the Glocks switch works well it just takes some getting used to.

I went with the G43x for the small size and capacity for my CCarry needs.

I always see CT grip lasers mentioned and personally don't like the position of the laser off to the side. The LM being centered under the Bbl keeps the laser centered when distance changes are made. The POI will change slightly up and down but stays centered.

I owned the CT grip laser for one of my Sigs and saw enough POI change with distance changes that a body miss would take place on distance changes at the range with a body size target. The CT laser is adjustable from side to side for distance POI.

The LM guiderod laser drops in and no adjustments are needed. Very simple!

We had Lasermax guiderods in our gen3 Glock 22s back in the early 2000s. They worked fine. Lens got dirty easily. We had to send a few back to Lasermax for new lenses. They didn't charge us.
I think we got them all in 2003 so it was the older loose spring design. In 2008, half of us switched the lasers to our gen3 Glock 31s. The rest sold theirs. I had to send mine in again and Lasermax sent back a newer captured model. I stuck it in the safe. I should probably go see if it still works.