It doesn't sound too bad to me. Real serious sportbikes like the R6 are sometimes driven very roughly, they are thrashed. I mean, that's what they're made for! So a bike can be really badly worn out in 11,000 miles. They are really racing bikes for the street and racing machines are not designed for maximum longevity and reliability.
But assuming the bike was properly driven and properly maintained, 11,000 miles is just 'broken in'. Most Japanese motorcycles will go 100,000 miles at least. Like Japanese cars.
When buying a used sportbike, you want to look at the previous owner. If he's a young person with lots of tattoos and jewelry, and he talks louder than he needs to, and he's always bragging about how fast he rides, then you don't want to buy a used bike from him . 8^) If it's a more grown-up person, then he probably treated the bike better. Buying from a dealer, you don't have that option.
If you could, it might not be a bad idea to take the bike to a mechanic you trust (if you have one) and have him look it over. This costs between $50 and $100, and he can tell you if the bike's been abused.
