I've just started tinkering with my 17 - and small things have woken it up (and it was quick in stock form, mine is a euro bike).
I've reflashed the ecu (Woolich), decatted with a good, free flowing exhaust and added a K&N filter just for the sake of it.
The ecu runs stock maps for now, with emissions features turned off (and the autoblipper enabled, it's a hoot :D ), the maps I've looked at that can be downloaded, I wouldn't touch with a ten foot pole...the bike will have the stock fuelling checked on a dyno next week - it runs very, very well.
And the front sprocket is dropped one tooth - and it's very, very lively at the moment.
Best thing to start with is a to get the Woolich Racing stuff, get rid of the emissions crap (carbon canister, KLEEN, exhaust valve).
And get a reputable tuner to work on the fuelling on a dyno, the autotune is a quick way to cut corners, but it still needs an experienced hand after the autotune has worked its magic.
Then take it from there, I wouldn't open the motor, very little gains for a lot of money on an already stressed engine.