Being in California I have a lot of Gen 3s and a few Gen 5s. I actually like the feel of the Gen 3s better with the finger grooves and blockier grips. All other things are not as important to me because I modify all my Glocks anyways (trigger, Magwell, grips, slide, etc..). If I were to compare them stock, the Gen 5s have a slightly better trigger. If you're a lefty go with Gen 5s for the ambi slide release and ability to swap mag release.