All valid points and opinions people.
From personal experience I was running 225/50/16 tyres on the back of my convertible and never noticed a difference in performance over the stock sized wheels. I know Seanick is running some pretty tall rear rubber, but he does have a few engine "tweaks".
If you are looking for an extreme wheel set up to compare any choices to then check this out, and no I haven't retouched these pictures:
Love it
