I suppose if you're dead set on an AWD drop-top, this is about it save for some big bucks (bigger bucks, natch) cars.
But, if I want a killer drop-top, I do prefer the Honda S2000. After some seat time in that bad-boy, I miss the VTEC slam-dunk.
If I want a power-mad AWD car, the STi is my target. At $34K USD, there is no bigger bang for yer performance buck.
While I love the looks of the newest SLK, and even the Z4 (lacking the retro look I adored in the Z3 though) and yes, the TT is one sexy beast, the Germans have big prices and suspect quality and I'm not sure that combination is the best...