I have a Gen2 G19 and been looking to jump on the Gen4 bandwagon...only thing worrying me is that I have quite a bit of aftermarket parts already vested into the Gen2, like after market match barrel, disconnector, slide release, TFO sights, DPM recoil and last but not least...AA .22 conversion kit. Will all my after market parts fit into the Gen4 without any issues, sans DPM recoil system? I think there is a bushing that I can buy to accomodate this? Also, there has been reported issues in regards to spring issue for Gen4, has this been resolved? Thx.