The Z1..many did not hold on..and now..it is so rare. At one time, people were selling it.
I think that it will be one of the really usable, tough, and maintenance free pieces that are always interesting at gatherings.
I see TONS and TONS of Lange and Pateks and gatherings..literally. So..if I spot a Z1...man...I want to see it. Especially how it has changed in patina...and how it responds to aging.
Damned good.