I put one on my Gen 4 G19 last week and so far think I like it. Much easier to activate with the trigger finger than reversing the OEM release. A bonus is that it will lock a Gen3 mag without the ambi cuts.

I'm looking for opinions from other users and those that may have had them longer. I like it, but want to be sure it's reliable in the longer term.

Thanks

I generally like it. Well at least the concept. The execution needs work.

It does bring some serious baggage, particularly with carry holsters. The Kydex shell of my Stealthgear Revolution didn't have enough clearance to clear the extended activation surface of the button on the MARS, which extends further forward than a reversed factory mag release and over the back of the trigger guard. The gun would fit, but depending on what kind of chair I would sit in it could release the magazine. The mag would not fall completely out of the magwell due to the holster's FBI cant, but now I'm left with a single-shot G23 (without first tapping the mag, of course something I never trained for). I fixed this by taking a Dremel to a portion of the inside of my holster to free up clearance space.

Another problem, even more serious: on my G19 MARS install, there were times that an empty mag would sometimes not drop freely when released using the left side button. The mag is typically held in the magwell by a catch 'ledge' that's on the right side, located under the right release button. Pushing on the right button causes it to retract into a nook 'within' the frame, thus allowing the mag to drop free.

HOWEVER with the slide locked back (like it is when the gun is empty and out of ammo), if I release using the left button a protrusion that's part of and under that button extends into the magwell and comes into conflict with the mag and prevents it from dropping free. Even with the weight of a FULL magazine it will not drop free. The open slide apparently imposes some undetermined force on the mag body, and coupled with the release protrusions and perhaps the catch itself, imposes enough pressure to only allow the magazine to drop about 1/8"-1/4" and stop dead in its tracks. At that point, the only remediation is to grab at the mag baseplate to rip the mag out of the magwell, or hit the right button that apparently upsets whatever 'hold' the gun still has on the mag body, thus allowing gravity to take charge again.

I think a serious session with that protrusion and the same Dremel that I used on my holster would probably fix the problem, but right out of the box it's my candid opinion that the MARS is a no-go for any carry or defensive-use Glock. I do like the functionality of the right release, but honestly the latter issue with the left release tells me that the MARS--in unmodified form--is simply not consistent enough for real-life use.

^^^

I agree about the holster modification. Easy, but necessary fix.

I'll have to try to duplicate the issue you described with the drop free.

I tested 6 mags tonight. Three Gen3 and 3 Gen4. I couldn't get any to stick using either the left or right button. Slide closed pops them with a bit more authority, but they all dropped free from a locked slide, too.