I don't want to discourage you from making an update, but the thought of all the things that might go wrong makes me point out the following:

- "Never change a working system" is great wisdom in general. If your setup currently works to your satisfaction, there is little reason to run the risk of screwing it up.

- As far as I know, Z12 did not receive any updates since 1.66. Are you sure there is some great functionality in the new version which would be useful to you?

- Every now and then I see posts about bugs introduced in new Zorro versions (or bugs that had been fixed before, but came back in the new version). Do you want to run the risk of discovering / or rediscovering a bug with Z12?

So in conclusion, if I were you, the only thing that could ever get me to change a setup would be a game changing new feature in the new Zorro version, which I absolutely must have. Otherwise, you bet I would not touch a working system!

Sorry for the rant. Just my two cents.