I would recommend to get the Z2 not the Z3 since the only difference is the overpriced second stage hose swivel that is permanently attached to the hose. You should buy a Z2 and buy a third party swivel and you will save lots of $$. I'd also buy a sealed Z2 first stage.
I came into this thread to post the exact same thing.
There is no good reason to go with the z3 over the z2 when you can swap out for a non proprietary hose/swivel for a lot cheaper than the atomic specific hose that makes up the difference between the z2 and z3.