In February 2012, I bought a G30SF, after having rented one a couple of times at the range. My 30 hated all FMJ, and spat everything at my head or whizzing by my right ear. Other shooters had the same problem. It also didn't like to return to battery. I sent it to Glock, and they replaced the RSA and (I think) the trigger assembly. I don't know if they replaced any other parts. Unfortunately, I still had the same problems, so I returned it to Glock again, stating in my letter to Glock that I would be happy to take a replacement pistol, if they couldn't fix the 30. After a few days, I got a call from a technician (Lee), who offered to replace the pistol. Since they didn't have a Gen4 30, he offered to send me a Gen4 21 but I asked if he could send me a Gen4 19 with night sights (as an offset to the price difference in the pistols). Lee said that wouldn't be a problem, and I got the 19 a couple of weeks later. The Gen4 19 works flawlessly with everything except PMC Bronze (go figure). I am very happy with the pistol and with Glock- they took good care of me.