Well considering only like maybe 1/4th of the z1's had issues and have been fixed and if they havent been fixed they are being replaced with z1a's... (because the place fixing the amps moved/went out of business). I'd say they should work.
Ofcourse they will work, will they have issues have issues, who know's? How do you expect any one to have those answers when the amp is not even out yet...
All I can tell you is that since the z1 issues, DD has put more focus into the amp build quality and has a new build house. The build quality is up the to the place that builds the amp, DD should/is going to spend more time checking the amps once they come from a different build house now... Yes thats right I said sent from a buiild house, like most, besides a select few companies *zed audio* DD have their amps built in places other than the US. But they are sent to the us to be checked upon from now on I believe.