I like to keep my RPM's around 7k or so. That way I have power to get out of the way if needed. Especialy if I am in traffic. It uses a little more gas, but my life is worth an extra $2 a week in gas! :mrgreen:
i dont think its necessary to shift higher than 6 all the time. If you are shifting at 4.5 than your probably not going to fast and shifting a whole lot. Your bike has much more potential after 4.5k that your probably not experiencing. Plus its way more fun. I shift around 6 around the city because the bike vibrates and the engine screams and works harder than it needs to. I think there still is a lot of available power if your going the right speed in the right gear. However on the twisties i keep it at least at 6k.
I ride around 4 for cruising ( traffic jams and school zones ). 6 for city riding ( perfect to lift the front in ) and minimum 7 for a hard ride. No use wasting over 10000 rpm shifting at 4 all the time. High RPM = high Power = high fun factor. My first bike was a '95' ZX-2R ( the real 250 Ninja ) and it had to live at 7000+ to get up n go. That riding style has transfered quite nicely to the R6.
All depends what mood i'm in. If i'm in a laid back mood i'll cruise around town 30-40mph in 4th gear. But! If i'm feeling playful i'll cruise around in 1st/2nd gear. Same on the highway... if i'm alone and just cruisin' 5th/6th gear. But if playing around 3rd gear till I need to hit another one. hehe