BUt hasn't he tricked the ECU to staying off limp miode and a few other things?
You defiantely should be quiet - I made 210rwkw on the stock turbo and a Powerfc for overa year, and was just a niave as most people here, coming in and claiming "250rwkw" or whatever just on a exhaust and filter, using the factory ECU.
I learnt, and understood how the systems work, and their limitations. I know most of these, hence why I know how to pick the dodgy dynos etc.
Sydneykid knows his stuff, more than you'll ever know, and I'm agreeing with him.