I’m a couple of days late to the party. I had intended to post on Wednesday, but our refrigerator broke so I had more urgent concerns.
The release itself went quite smoothly. I have not tried to install with the final installer. But I have installed some of the pre-release versions. And those went very well. Most people seem to be installing without problems.
Leap 42.3 is only a relatively small change from 42.2. It is still at Plasma 5 version 5.8.7. As I recall, 42.2 was released as Plasma 5.8.2 or 5.8.3, and later updates brought it to 5.8.7.
The main change that I am seeing with the KDE desktop, is that now “konqueror” comes from Plasma 5, instead of being the Plasma 4 version. However, “rekonq” is still from Plasma 4. And “Amarok” is apparently from Plasma 4.