Yeah, dirtbike and sportbikes don't have tons in common. Put your foot down on a sport bike to take that sharp turn and see what happens. As a matter of fact, the guy who rode dirt bikes all his life (and his helmet and riding gear was dirty enough I believe him) was the only guy to get kicked out of the class and told to come back later, after a weekend on their simulator. He dropped his bike 4-5 times and bent the handlebars on the last one.
The FZ6 or the R6 is really all the power you need on the street. And all the power you need for a lot of race tracks. I went with my buddy the other day on his shiny new GSX1000R to the track and watched him get owned every corner by 250cc bikes. Sure when the corner was over he blew by them, but they passed him every turn. I think he was the only guy that left with chicken strips.
So don't worry about it. I started getting bored with my bike after awhile, and I test rode a R1... I'm happy with my bike. There was so much power that you couldn't even use more than a quarter throttle anrywhere. Full throttle in first gear from a standing start will loop you. Full throttle with the FZ6 will loft your front wheel in the air about 2-3 feet. Try it. Rev to 6-7k and hold it, dump the clutch when the light goes green and snap the throttle to it's lock. At about 11k start easing the clutch in so the wheel goes down slowly, then when it's down, snap to second and nail the throttle back open to 100%. Wheel comes right back up. Rinse and repeat, but it won't come up in third. Not to mention you should probably slow down now. How boring is the bike now? Welcome to doing a quarter mile in 12 seconds or so, and topping out near 120mph. Just 20 years ago, drag racers were celebrating breaking the 12 second run.
The biggest thing is that the reaction time for mistakes on a liter bike is almost non-exsistant. You hit a pothole with your arms locked and that throttle goes from 19% to 80%, you're gone, seriously a buck-20 just like that. And if you didn't keep the bars straight while you hit the hole... Hope you AGATT.
If you want one, great. Just keep this bike for awhile first. I'd say a year if you ride everyday, and longer if you're a weekend warrior.
And as far as the gas goes, you do know that F1 cars run on pump grade regular octane gas right? And they're just about the only car that can match the straight line performance of a liter bike. Those and Top Fuel dragsters.