There are things about that much hp that decrease life, if you use the hp. The stock turbo isn't designed to move that much air and is either spinning too fast or your not cooling enough.
Shiming the rail means your running high rail pressure, and that's the number one killer of injectors. . hopefully you aren't running out of the box filter on the AD as that's less overall filtration than stock (unless you kept your stock filter as well).
There are plenty of people running high hp machines, but 500 rwhp is a bit above what most run, and is easier to find yourself out of the reliable realm. 400-425 rwhp is about perfect on a stock motor. . Above that and your looking at studs, serious trans upgrades, turbo (for useable power, not just quick blurps of WOT), CP3 upgrades, airflow improvements, etc. . But like you mentioned it does work well for plenty of people, but not what I would advertise as an improvement over stock in the reliability/durability dept. . with stock parts.