I had a 30" Z-1 for a couple years with a sniper tip. Bought a 30" Z-2 when they came out. Hated it first night! My cueball did not react like I was accustomed. I hoped it was the tip, and installed a sniper like I had on the Z-1. That was the ticket. It played just like the Z-1 after that.
So to me, they move the cueball the same. As far as feel, I don't feel any difference between the two shafts on the same butt. But I know others have said the Z-2 feels better. And for the record, I never had a problem with how any Predator shaft felt like many others have (been using Predator shafts 10 years now).
As far as the ability to keep the ferrule clean of chalk, it is a bit better than the Z-1, but still bad compared to other materials. The ferrule is still soft and I can see slight flat spots on it after a year of play and the ferrule sliding on the table on follow through - just like every other Predator shaft made.
My personal conclusion is if you need a new shaft, get it. But it will be the same as your Z-1.