The Glock Generation 4 pistols have a handful of changes.

These are Steve Koski's impressions based on side-by-side shooting, fondling, and tearing down Gen 3 and Gen 4 Glock 17 9mm pistols.

        Download the PDF here.

including all 26 color 8"x10" glossy photographs with circles and arrows and
a paragraph on the back of each one to be used as evidence against him