If you are the type to enjoy what you have without worrying about what others think of it, you will probably like the YZF-600 quite a lot. It is known for being a very capable and fun middleweight sportbike. It has a more comfortable riding position than the R6 and other repli-racers.

While it may have less "street cred" than one of the more hard edged bikes, if you take the time to really learn how to ride, then you will likely be able to make it perform quite a lot better than the average sportbike rider can make his "superior" bike perform.