My main workstation refuses to update. I had nothing but problems with it trying to update from 8 to 8.1 previously too, to the point I had to buy an 8.1 license and do a clean install. Not sure what the problem is. It's not old, and it's a beast of a machine, but there's something about the hardware configuration that these updates don't like. I'm not too keen to be doing a clean install right now and getting all my programs reinstalled, so unless I can figure out what the issue is, I'll be on 8.1 for awhile.
I did do my laptop though, and it updated fine. I don't use it for much other than for viewing web work and for DJing, but I haven't had any crashes or other problems yet (touch wood). I'll do the home theater box this week as well.