I am like Don in that I have six computers running Win 10.  No problems, still frequent upgrades which seem to improve performance most of the time. 
Well, I do have one problem, my scanner software from Hp does not work with W10, and Hp does not offer an upgrade.  I have two scanners I cannot use except for one older W7 version I seldom turn on anymore.  I consider this a Hp driver issue rather than a Win 10 problem.  Hp does not seem to want to upgrade my scanner driver, they consider it obsolete, but it works great on any Win version other than 10.  All other drivers for other devices have been upgraded and work fine.