We are authorized to upgrade the guns with the latest parts from Glock, from whom we receive the latest parts lists and components. Any work we do to the guns, provided it falls within our scope of practice, does not void the warranty, and we have support from Glock. Any dis-assembly beyond the basic field strip by a non-certified person will void the warranty. It also means that we can diagnose and correct any issues with the guns rather than them having to be sent back to Glock, and the work is warrantied.
Additionally, some of us have over 25 years worth of experience working on the guns, and those of us who are Advanced Armorers, and who have trained at Glock, have had access to examples of every conceivable problem with every generation of the guns, and pretty much every model, including the latest 42.
Regards.
Mark