There's a trend with the recent Kawasaki sport bikes, in that their design effort seems focused on engine "blunt force". The 1000cc 2006 ZX-10R is a muscle monster, a huge engine on a lithe frame. Perhaps like no other bike it requires huge respect from the rider. It doesn't like fools or people lacking self-restraint. An outstanding bike by any measure.
But may I suggest something else instead?
Triumph Daytona 675:
This is more like a japanese sportbike than a classic Triumph. It has 3 (yes, three) cylinders, so it's in between the typical V-twins and the 4-in-line designs.
At 675cc, it has more oomph than the typical 600cc bikes.
It's the most lightweight and the narrowest sportbike currently on the market. While sitting on it, it felt pretty much like my late ZX-6R, only more narrow. Maybe a tad taller too? I dunno.
But the nicest part - it has a crapload of torque at the bottom end and in the midrange. E.g., at around 6k RPM, it has almost 2x more torque than the Yamaha R6, while also being lighter.
In a recent 600cc comparo, it outperformed everyone else (including the Big Four japanese bikes) in the quarter mile and in the 60-80 and 80-100 acceleration tests.
The bottom line: it's probably a better bike to ride on the street and in the canyons than a normal 4-in-line. When taking off from a stop, you will have to rev the hell out of a 4-in-line to get decent acceleration, while the D675 will jump ahead efortlessly without making the engine sound like you're a week-end racer wannabe.
On the track, let's say the similar bike from Yamaha may or may not beat the D675, but you'll have to keep the Yammie revved up all the way to the ceiling all the time and it will slow down miserably as soon as you drop below 10k RPM, while the D675 allows you a more relaxed approach.
Oh, and... this is subjective, I know, but it's a beautiful bike and the engine sound is very nice (again, a bit similar to my late 03 ZX-6R - due to the intake, it sounds like a turbojet revving up).
Check out the on-line forum:
If I ever get back in the saddle, this is the bike I want.