I have 8.164 running here on two systems - desktop and laptop - both a few years old now, not super powerful by today's standards - and they both run X3P just fine, smooth and stable up to the limits of the hardware they're running on.
I have never understood the bizarre intense kneejerk negative reactions to Win8, as far as I'm concerned it's a great OS, robust and user-friendly and full-featured, and has been pretty much since release. I like 8.1 a bit more because it seems a bit more refined all around but the rage about the Start button/page remains a mystery to me - not because I love the Metro interface or even use it or look at it very often, but because it really doesn't affect me at all. I use the desktop most of the time, switching if I need to search for something.
So in short, in my experience, it works great and W8.1 is a very enjoyable environment. My two shekels, ymmv as always...