I can't tell a difference between the two. Your mileage may vary.
There is one for sale over here for $710 US.
Having a bit of a shuffle around.
Is the CX A5000 based on the Z11 preamp?
Do you use a 12v trigger to turn on the Z9?
On the Z9 the Dynamic Range settings what do you have yours set to?
The manual pge 70 is a bit confusing the way it is worded or is it just me.