Broken OS
I normally resist OS major version updates on Apple until the .1 release (much like I used to on Windows) in order for all the beta testers to find the main issues in the OS. I then take a view on whether the issues that occur justify updating the OS major version using the .1 release or adopting a further wait and see approach given they usually go up to a .5 release.
In this case I think High Sierra is just utterly fucked and I'll miss the whole thing. I'm sure, if he were alive, Jobs would have disembowelled someone with magic mouse by now over the shitty quality control that now seems to pervade everything Apple do.