the standard intake is very good.
I wouldnt advise induction kit on a turbo, it gets too hot under the bonnet regardless of shields and cold air feeds, which are useless in traffic.
I tried a friends modded air box for an few hours, but again didnt like the idea of all that heat being sucked up , it felt more laggy low down, and more promenent DV noise annoyed me.
i replace my paper audi filter evry 10K or sooner and still hit repectable RR figures and MAF airflows via vagcom.