There are no turbos in '11. They are in the '12s as a GLI (unless you're talking TDI).
I have not had the chance to drive a GLI, but from what I've read, it's a better Jetta, but not as sharp as the previous-gen or a GTI. If you're looking for something along these lines, get a GTI, find a late-model GLI, or a 2010 Wolfsburg Edition (in that order).