Sometimes it fails to recognize one of my two external monitors, and when I wake it from screen saver or screen off (energy saver, but with laptop still running), it flashes the three displays a while and fumbles around trying to decide what goes where before _finally_ allowing me to unlock. And after I unlock, all my windows have been rearranged and shoved onto one display.
I find no improvement or redeeming value in High Sierra. It's almost as bad as my new Windows 10 laptop next to it... in fact with the crashes it's now even worse.
Apple has been on the path of self destruction, dare I say, since Jobs died. He may have had some goofy ideas, but apparently his dictator like control and obsession with details was worth more than I realized. Sadly for us users, especially developers, we'll soon have no OS that works great all the time.