Having owned and worked on more Glocks than I can speak of, I have more than a few opinions about them.
First, I will say that I actually prefer other minimal modifications.
What I need is simple:
Steel sights, preferably nite sights. (Tru-Glo TFO, Meprolight or Trijicon)
Trigger modification (contouring the trigger safety bar to the trigger face)
I normally cut the magazine release down, removing the serrations and rounding the edges on it. For concealed carry it’s much better.
Here’s one I used and carried for a number of years, used on duty and in a number of classes.
One other modification I like is a grip modification.
In my case, the arched housing area on the back of the grip frame makes the gun shoot high when shot instinctively aka point shooting, and I have to ‘break’ my wrist to shoot targets with a proper stance/grip.
Here’s a G21 that I used for over a decade, with the backstrap modification, the finger grooves removed and cutouts for stuck mag removal.
I wore the stick-on grip surfaces off repeatedly, finally retextured the grip area with a surface that was both aggressive and yet concealable.
The Pearce (and other) grip plugs can be nice but also leave a place for junk to collect from the top.
I’ve had both good and back luck with them, but with my modified grip frame, that area is filled in and the plugs don’t fit anymore, but the effect is the same.
I still don’t like the ‘small’ frame Glocks, they don’t fit my hands right, even after modification.
But I do have a G30 tucked away behind my hip.
Lightly modified of course.
Here’s a trio of Glocks including the previously mentioned 30 and 19L (cut down 17) and a 20 with ‘treebark’ texturing that I’ve come to favor.