And I think your comment about new bugs slipping in is a fair statement.... the addition of the editor is really a pretty massive change to the existing Rig Manager, from an engineering standpoint. That's a whole lot of new functionality, any of which could have bugs.
Also note that except for one crash, there weren't any major bugs reported for the editor or how RM 3.0 and the editor work together (cheers). What we are seeing now are quite a few bugs mostly related to performances, storing, switching and copying slots, creating new ones.. all the things you are not having in mind when testing and developing an editor
I was a little surprised that either so many people did not even try to manipulate single rigs and play around with it or that it goes so smoothly that mostly issues with performance management come to the surface now.. Looks like until NAMM we will focus on getting performances stable there.
The 125% on Windows seem to trigger the problem. For some people everything goes back to normal with 100%. It's not so easy to tell "why" though, so sending reports with as many details as possible is always helpful.