Bought myself a Gen 4 21 to go with the other Glocks today. If the weather is nice I'll try and get out to shoot it tomorrow. As an unofficial test it was drilling walnuts at about 23 yards tonight with the rain, my TLR-1 for light, and firing Ultramax Ammunition so not too shabby. Here are some pictures in the mean time.
From top to bottom.
Gen 2 Glock 17
Gen 3 Glock 17
Gen 4 Glock 23
Gen 4 Glock 21
From top to bottom.
Gen 2 Glock 17
Gen 3 Glock 17
Gen 4 Glock 23
Gen 4 Glock 21