Mares Proton 42 She Dives vs Atomic Z1 regulator

[paulwlee]

Both regs are good regs - The Z1 has been updated with the new piston and is now the Z2. Z1s can be updated with normal maintenance become a Z2. If a used Z1 I would want it to be been updated with the new piston otherwise I would pass.

The Jet piston upgrade kit costs ~$80 if I remember correctly.
You can tell by looking at the HP seat cap (on the opposite side of where the LP turret is). If the cap is mostly covered with rubber, it has the new piston. If the rubber piece over there is instead donut shaped, exposing the HP cap, then it has the older piston.
A Z1 first stage with the new piston is the same as the Z2 first stage.

The Z2 second stage has a slightly different outer body case, and I think a new exhaust tee, but I doubt that it really makes a noticeable difference. The new tee can be put in place of the old one if you desire. I think it costs just about $10.

 

[Thalassamania]

They are both fine regulators, each an example of the pinnacle of where evolution of that type of regulator is. For me the question is "piston or diaphragm?" I come down on the side of diaphragm for a number of reasons ... so it's be "She Dives."

 

[iflyprops]

Sorry to hijack a bit but what is different on the pre 2005 vs post 2005 Z1's? Is it worth updating?

 

[paulwlee]

Sorry to hijack a bit but what is different on the pre 2005 vs post 2005 Z1's? Is it worth updating?

The Jet Piston is supposed to slightly increase flow rate, which probably makes zero difference to the user, but more importantly it makes the IP less susceptible to creeping. With the pre-Jet piston, on occasion especially with heavy use of HP tanks the IP would start to creep a little before the two year service interval.
If you have the previous version and are not seeing the IP creep, you don't really need it.