great bike. i only have about 2000 miles on mine but i love it now. truthfully, i had a couple small issues on mine that i've just now sorted. but almost all of that was due to aftermarket modifications. i have ohlins suspension and the oz lightweight wheels on mine. so take that with a grain of salt. the only issue i've had with it in "stock" form is that the dashboard had a couple defective number on the odometer. they replaced that a few weeks ago and everything is good.
as someone else mentioned, it is in essence a comfortable mille. i'm about 6'2" and 250# with a 34" inseam. the tuono is pretty damn comfortable for me. it's a tall bike, which works out well for me. i had adjustable footpegs on to give me a little more legroom and now it's really perfect. although i met a guy up here a few weeks ago who also had a gray tuono and he was probably around 5'6" if not shorter. i asked him about it and he said that he hasn't really had an issue with the height. go figure. i had a falco before the tuono and the position was just a little too aggressive for daily driving. but the tuono is a perfect compromise. the wide handlebars make riding the tuono feel like a mx bike (from what i would gather). the leverage is really great and you find yourself kinda throwing the bike down under you in some turns.
power delivery is what you would expect from a twin. nice low end with lots of torque. the thing wheelies at the drop of a hat even though i'm terrible at wheelies. from the factory most aprilias have an odd flat spot around 5500 rpm. it's nothing that a good pipe/slip-on and new efi chip can't fix. i have a power commander on mine and had a renegade slip-on and chip on the falco.
my suspension isn't stock for a standard tuono, so i don't know if my comments will help you in that regard. but i do know that i've just raised my forks into my triple clamps by three lines (ohlins) and it's turning in great. but the other tuono riders i've been with all seem to find the stock suspension set-up really good.
the bike is pretty flickable for a literbike and the ergo's are good for both aggressive street, track or casual riding. it's a great all-rounder. honestly though, for a true all-rounder i prefer my zrx. the tuono is really a race-derived bike and you can feel that it's a little more "high-strung" than the zrx, which is pretty much a straight-on street bike.
i haven't tracked my tuono yet since i bought a much cheaper bike to play with at the track. but a lot of the guys at aprilaiforum have been all over the track with theirs and only have good things to report. the only downside for a tuono on the track is, of course, the weight distribution compared to the mille. take a full-on race bike and then raise the bars so that there's less weight over the front wheel and figure out yourself what happens. but it's very manageable i'm sure.
wind protection is surprisingly good for a naked bike. at my height the windshield deflects the wind to hit the top of my helmet. so not very much buffeting and the hands are actually out of the windblast due to the little design elements right around the grips.
really a fantastic bike. if you're looking for one i'd suggest looking for a used one. they're popping up now and aprilias traditionally don't hold their values all that well. there are a few for sale on apriliaforum. there's even an "r" model for sale with lots of mods. lemme know if you have any more questions. i know bbqchef has one and i think one other tuono is running around in the euro forum.