I own a Glock 19, but I changed the guide rod to a tungsten guide rod, put a new trigger in it, extended slide stop, extended slide release, meprolight night sites, grip plug, and extended mag release on it. The performance of the firearm has changed very little, but Glocks are very simple to customize, and make your own. I will try any firearm out ,and give it a chance. I own a Sig Sauer 1911, which in my opinion, is hands down one of the best 1911's I have shot, but I will always have a Glock in my gun safe. They are without a doubt one of the most dependable handguns on the market.