I am in the process of selling 1 more handgun and getting a Glock to replace it. I have already sold one and I just recently bought a Glock 21 gen 4 to replace it but I haven't had a chance to fire yet. Then I want to purchase the Glock 17. This will hopefully allow me to transition back and forth between the G21 and G17 easily, in which most of my shooting will be done with the G17 since it will be cheaper to shoot. Seems like there are no issues with the G21 gen 4's but when you get into the G17 & G19 gen 4's, it seems like a hornet's nest has been knocked out of a tree. I thought I would be safe going with the G17 gen 3 but there seems like there are problems there also - at least with the most recent ones manufactured. Are there certain serial numbers in the G17 gen3 that would be reliable? It seems like it is a crap shoot on the 9mm platform.