hmmm..depends how you ride and what you want to achieve on the bike.I don´t think a rookie can master truly a 600 cc supersport machine that could easily outrun a 250k $ Lamborghini Diablo with ease.The point is that any bike could be learner bike.Even a Busa or a ZX10,the things is that after you get learned how to ride you won´t to use more and more power.So if you are learning on a powerful bike you´re not prepared for its grunt.And..this is the reason why so many new riders on big bikez crash.For me you have to become the master of the bike before you moove to a bigger one.you have to be fully able to predict what it shall do.When you´re able to do that-you´re a rider,a rider ready for a bigger challenge.You have learned how to ride on the 600 cc engine motorcycle.But have you studied all the tricks of countersteering,sliding the rear(even the both),the tricks of the relationship between your suspension settings and your personal weight,the triocks of throttle control,have you?If you have then congratiolations!If you haven´t well..go on bro! If you got any questions write to my email-I only check it not the web site-kawasaki_zx10rninja@abv.bg Peace