I bought a Tuono V4 two weeks ago. Only done 100 miles so far and half of those in the wet. It's all about the engine, it's awesome. Even running it in below 9k it feels quicker than the S3. Ergonomics are about the same. Handling wise feels slower to turn in but my S3 has BST wheels.. Too early to tell how the fast handling compares to my 06.
Looks are still growing on me, I think the S3 has the edge there. Also the Tuono isn't happy in heavy traffic like my speedy is. It's more of a sportsbike with fairings taken off.
They are doing great deals on 2012 stock right now. Sadly means the Triumph will be going next spring
Also the Aprilia forum sucks!