Well if you don`t care about your MPG (I mean comon, it`s a difference of what, $2 or $3 per tank??? I don`t get why anyone would care), dropping a tooth in the front just gives you more "useable power"... in other words for any given speed, your rpm will be higher compared to stock.
So say with stock gearing you are cruising at 50mph @ 5000rpm in third... now you`ll be going 50mph @ 7000rpm in third, or in other words you`ll have more torque available to you for that speed... and this goes pretty much for the whole powerband.
Now, the side effects:
- speedo error increased (I don`t care I have the koso

)
- less MPG (I don`t care about $2 a week difference)
- less top speed in each gears (on the FZ, you won`t notice a difference in top speed)
- higher engine buzz at any given speed (obviously)... noticable difference above 80mph, but nothing bad.
I`ve been experimenting with it all day yesterday and for me, it`s the best mod I`ve done to my bike by far. It is smoother and just gives you more torque for city and freeway driving.... great stuff.
Plus you can try it for $30... if you don`t like it, put your stock sprocket back on and sell the other.
Cheers