The RC 51 is more comparable to the modern 600's in street performance..Actually on the drag strip the CBR 600 and R6 are faster than the RC51..But get the RC51 on the track and you will see who shines..The reason they make it, is for racing applications..You have to produce the bike for consumers in order to race it..It fits perfectly into the designated class..Up against Ducatti's and Aprilia's .It is an AWESOME track bike..Well balanced,great brakes, and lots of torque to get you out of turns..