If you're considering a Glock in 9mm or .40 caliber, this video is meant to help you make the decision.
Glock 26 - Baby Glock in 9mm
Glock 27 - Baby Glock in .40 caliber
Glock 19 - mid size Glock in 9mm
Glock 23 - mid size Glock in .40 caliber