I don't say any of this to bash this company or product, in fact it is just the opposite. I love this product and company and have recommended it / them to several friends. I do, however, think several improvements can be made.
First and foremost, watch the install video. This was make your install much simpler (filing down your feeders is a must, but you don't need much). Here is the problem I have. It is sold as a +6 extension. In reality, yes you can fit 23 in the magazine. However, with the slide forward, you would have to use a hammer to get a 23 round magazine to lock into the gun. Slide racked to the rear, no problem. This just is not practical for a duty carry magazine though. To solve this, I just want to +5. It still fit snug with the slide forward, but much much less force required to seat.
This brings me to my second issue. The install video recommends to "stretch the factory spring" to give more force for the increased capacity. Please don't do that. I was getting a failure to slide lock on about 80% of my last shots, even with the springs stretched. I never had a feeding issue, but this is also not acceptable for a duty carry gun. I upgraded to a plus power spring (you can find them relatively cheap elsewhere) and it solved the issue no problem. Further the springs had returned to the normal size when I removed them. Unfortunately this reduced the capacity to +5 (but the same issue as above persisted, so I carry with +4 now). 21 is still better than 17, but it isn't 23 obviously. These are just my two cents in what I experienced with the two I purchased.
As far as the pros: this company is great to first responders, so I appreciate their support.. Also, the exterior profile is great. It looks much nicer than the other ones I have seen floating around from other companies (including much more expensive versions from more well-known brands). The side grooves make for easier reloads, especially when combined with their magwell IMO. Even the logo on the base is sharp and not overdone. The coating did scratch each time it was dropped from less than three feet though. Shipping was also very fast. After you file down the feeders, installation is super easy.
Buy with confidence, but know the limitations. Stay safe!
Reviewed by: Steven Prats from Spring Valley on 11/11/2020