The trouble with modern superbikes is they way more power than you can use on the highway,so you ride around using a fraction of their capability,whereas The Z you can wring its neck a bit which is far more satisfying,and a well ridden one will hold its own in the twisties with more powerful machines,of the many bikes I have owned 2 stand out for the fun factor a 600 Ducati monster and the Triumph street triple, niether could be classed as a "superbike".I lived in Germany for quite a few years and one of the bikes I owned there was a Kawasaki zzr 1100 which at the time was the fastest factory machine available,and on the unrestricted Autobahns I saw 170mph more than a few times,but on twisty road was no faster than a well ridden 600.