Thanks @teddy875. z2 is A2836? It's still unreliable? I guessed probably a new batch with minor changes rather than major improvements.
Looks to be the same z2 movement. I compared to my steelfish and nothing jumps out to me as being different to my v2. I'm sure there some minor differences, but the movement, which is what counts most to me, is the same and since the v2 is a super rep already, there's not much room for improvment. The stamping on the bracelet looks comparable, the print on the dial comparable, lume comparable. Probably like the PAM 111s where there are some false"v4" that are a mixture of new and old batch parts. Still a beautiful watch regardless, and the good thing is if and when the z2 dies, it's a direct swap for a 2836 (except for the date wheel)