I've a Pearl White `07 CBR600RR with HeliBars, stainless front lines and Sato frame sliders, -2 rear sprocket; LED turn front signals the previous owner put on. Other than that, it is bone stock.
I went 2 teeth smaller on the rear sprocket because I think the engine has enough guts to pull it. It doesn't power wheelie in first like it did with the bigger stock sprocket, But it's not wailing in 6th like it used to, either. On the other hand, spinning that little engine gets to be habit forming in a hurry! The speedo is pretty accurate now, also.
It has a good suspention under it. Not great or perfect, but pretty good. I get tempted from time to time to stick an Ohlins under the thing, but the stock rear shock is pretty ok.
Mine is very comfortable. If I could get another 1 1/2 inches of legroom, it'd be just about perfect.