General Comments:
This bike is a wonderful commuter and has served me well. It doesn't matter if you are riding two up or on your own, it will do the job quite nicely. I have only needed to make minor modifications to it, taller windscreen, mirror extenders, and rear peg extenders for my wife to be a bit more comfortable.
My only knock on the bike is the stock seat. It took a few thousand miles for the seat to wear into my rear end enough to make it not fall asleep on rides longer than 50 miles.
The power of this bike is really all that 90% of most riders will ever need in the real world. Tons of torque that starts at very low RPM's and continues well into the upper power-band. It really has a lot of power. The only bikes that would smoke the the ZREX are the hyper-bikes of the world like the busa and upper level ninjas and R-1's. But, in my opinion this bike counters the lack of that kind of speed by its all around utility.
Its not a home run power hitter, but it is that guy in the lineup that will get you a hit every time you really need, year after year.
As far as the suspension goes, I am not the corner hugging canyon carver type, but I have never felt this bike wouldn't do exactly what I ask it to. Confident and competent are very good words to describe it.
Just like so many other Kawasaki engines, this thing is nearly bullet proof. No problems at all. just change the oil (go with a full synth for the smoothest shifting) and change the tires when they wear out.
As far as the styling goes, the retro look is not for everyone, but if you are into that sort of bike, then nothing comes closer to the old sport standards than the ZREX. If this machine were available in 1982, it would have been outlawed by the insurance companies.
By the way, the Blue ones are faster than all the other colors. :)