I've had this model 23 since Dec. 1992, bought it new. I've never liked shooting it very much due to the sharp ridge on the cutout where my pinky goes. The old Glock pistols used non-drop free magazines and had the cutout to allow faster pulling the magazine from the pistol if needed.
I finally decided the ridge around that cutout was going to disappear. With a Dremel tool and sandpaper the offending ridge was removed and the pistol felt better. However, I felt like it could be improved further still, so I put AGRIP on it. I did not simply install the AGRIP, I modified it too. As it comes from the maker, it would cover the magazine release and be up under the slide release; I wasn't too happy with those aspects of the intended fit.
The feel of the old model 23 is significantly better with my recent modifications.
I shot it and found it more comfortable to shoot than before. I had always had a piece of bicycle tube on the grip, but the ridge wasn't covered and it didn't take long for my pinky to complain. With the ridge gone and the area covered in AGRIP my pinky finger didn't get abused.
I shot 3 different loads over the chronograph, here is the average for 5 shots:
Winchester "white box" 180 JHP @ 977 fps / 382# KE
Winchester Ranger T 165 gr. @ 1,125 fps / 464# KE
Speer Gold Dot 155 gr. @ 1,171 fps / 472# KE
I shot when the temperature was approximately 90 degrees.
I did some "double taps" with the Ranger T. My goal was to keep both shots on the 10 area (a 4'' by 6'') of a B27 target from about 6 yards away (18 feet). If both shots didn't stay on the 10 area I didn't count the time. I was only interested in speed of follow up shots.
My best 5 double tap sequences that met the accuracy requirement averaged .47 between shots (I know, I'm slow).
Fired cases exhibited a solid hit on the primer, and no bulging. Cases were ejected a few feet to the right about parallel to where I was standing.