I k04 my gti. Put the turbo and injectors on myself. It's a right pain in the arse. Took me a weekend on the driveway. Got a revo stage 3 map. Goes like stink. But now I need clutch and it is pushing the engine to its limits. Personally I wish I bought an ed30. It's a lot safer. Also I wish I had dsg as I wouldn't have to worry about clutch issue.
Don't get me wrong it drives lovely on part throttle round town and when foot down it flys. But it is a lot of work and money. And it's never going to be as safe as ed30.