Reinstalling Windows 8.1 made the problem go away. I'm really not satisfied with that as a solution since I have no idea what caused it, but at least the issue is gone...
I'm hoping I can just live with the occasional freeze up and that MS can address them in the by and by.
I load so many desktop apps for my job, each with its own custom settings, that I'd not be a happy camper to have to start back with a fresh 8.1 installation..
Glad though that your experience is getting better...
Also, in my case, some of my freeze ups are turning out to be app bugs, I think. I mentioned xbox music before.. I found that if I search for a song and then click on it (instead of browsing for the song and then clicking on it) the UI sometimes displays correctly and sometimes doesn't.. When it doesn't, it gives the appearance of a freeze-up .. that is, you can click on a song name until you are blue in the face and nothing happens. But then other times when you click on the song name it starts playing, as you would expected. So in that case, I don't think it's an o/s issue per se, though I can't be 100% for sure.
Michael