https://news.opensuse.org/2015/11/04/opensuse-leap-42-1-becomes-first-hybrid-distribution/
Remarkably smooth transition.
A few minor irritants:
• CUPS / HPLIP / Printer. Initially the printer fails with "Filter Failed". We tried reinstalling CUPS, HPLIP and various other contortions. Finally, by googling and finding
https://software.opensuse.org/download.html?project=Printing&package=hplip
we installed a new repository for hplip:
http-download.opensuse.org-9027b0d2 | Printing
This then found a new version 3.15.11-133.1
This solved the problem. Hope Google makes this helpful to someone else.