Haven't had any issues with the stability of Win8.1 yet, but the user interface was terribad, so I installed Classic Shell the moment I'd installed the OS. So far, though, the only positive thing I've noticed has been the shorter boot times, though, I wonder how much of that is due to the SSD.
I've encountered many oddities that seem to imply that the B-team was working on this operating system. Like the fact that you can't change the color of window titles. You can change the background color (when you change the color of everything else), but not the text color. Black text on a dark background is just @#%^ing amazing. Good job, Microsoft. Although, I could always choose one of the high contrast themes. THEN I can get a different text color, but everything else looks like a kid ran amok with a handful of crayons.
Terrible, terrible design. Thought they'd have fixed it in 8.1, but nooo... why should they. Who needs window titles, anyway. Can't see that sh*t on your tablet, can you? Priorities, people!
____________________________Please "talk up" if your comprehension white-shifts. I will use simple-happy language-words to help you understand.