I'll start first at my laptop. It is old, the model first came out in 2007 and so many things on it are no longer supported. Win8 is pretty good about figuring out what to do with most of the drivers but the wireless driver has issues. Every now and then it will crash the system. This gets annoying real quick and can happen anytime without notice.
I hate the default visual style because of the white border thing with out of focus windows. So naturally I mod the system and use 3rd party themes. Since Microsoft has chosen to make themes and msstyles so weirdly processed and instantiated and patching any system files will just simply cause the system to not work after any update. UxStyle has an awesome way around this without patching files. However, every now and then you will have uninstall and then reinstall UxStyle. After awhile I found that this has the probability of causing problems.
Now onto the biggest issue, the black screen of death at login. You will only see your cursor and nothing else. Only way to fix it without losing everything is to use a restore point. This has happened on both my desktop and laptop. I'm not sure of the real reason of the cause as it could be multiple things like UxStyle, Avast, or win8's fast boot.
I'm tired of all of this and I'll probably stick with win7 until the next iteration of windows comes out or win7 support is dropped.