>>636 engine alone would not be enough to put the ZX on top. The kawasaki chassis would have to do its bit<<
I might have thought that the USD fork, radial brakes and (on the 600cc version) slipper clutch and adjustable swingarm might have helped as well. Of course, since we can't get the actual text of the article without forking out $350 to subscribe to the print rag, we have no idea what led MCN to that conclusion.
Quite frankly, as JohnnyB stated in the recent Honda writeup, they are all so much better than 99.9% of us will ever be able to use, that the choice really comes down to brand preference, aesthetic preference or the local dealer.