I would take the 911T since i still have use for the rear seats and prefer the sound of the 6 even though the Cayman is probably dynamically superior.
Edit: now after I wrote above I actually way prefer the T, if I had the money I might get but new Cayman has no interest to me. Actually I would prefer a used cayman with the 6 over a new one. Guess if you offered me a free new one or a used one I would probably take a new one