Whole different animal. The zx is based on the Honda Dio's af18 engine. The biggest advantage of this engine is the parts base for the Dio. EVERYTHING for the Dio works on the zx. You can build them up to 125cc's for under a grand.
The biggest draw back is this is a discontinued engine so not all shops have parts in stock, and it may take a few weeks to get most parts.
The zx is a solid bike w/ really NO inherent flaws. Bone stock they suck monkey wind but a cvt tune up, and decent pipe they will do 50mph all day long. I've had two BBK's on the original cases, and have run the scoot over 70mph with no issues. The bars tend to rack a bit over 60 but not enough to slow out of it. It also sits like a much larger scoot. 34" seat height, and plenty of room to stretch your legs forward. I found by lengthening the wheel base 3 1/4", and lowering the scoot 2 1/4" it handles much more predictably.
The factory wheels are pretty nice too 4" wide aluminum. Using bolt on Schroeder valves you will have no worries.
I like the scoot more than the S9 simply because it is a little tamer or easier to ride. Sort of like a cafe racer vs. a rice rocket.
The retail blue book is 936.00 as of today. Trade in is 4, and change. I found mine for 300.00 w/ 13K, and near mint condition.
Just hit em up with the "It's a discontinued model! Why on earth would I pay xx dollars for a scoot I can't even get parts for" "Come on honey. I want to go buy the one at Pep boys for $498.00"
It really don't take alot to "tighten" one up either