On start up sounds a little diesel like if i'm honest!! 
I had read this and was relieved to discover my GTI doesn't sound like a diesel at all. However, I recently had the chance to drive my brother-in-law's Audi TT 2.0 TFSI for a couple of days (same engine as the MkV GTI) and that did sound like a diesel for a second or two on start-up. During normal driving, however, it made almost no noise at all; very disappointing compared to my GTI.
I am beginning to wonder from reading this post if each car isn't tuned differently (although I can't see why VW would do this).