Keep windows 10 or "upgrade" to windows 8.1?

I built my first diy pc this past year, my previous pc had vista and I was just going to use that one's hard drive. Turns out my mobo doesn't like vista (much like any sane person) so I downloaded the windows 10 tech preview to use in the interim. A fresh copy of windows 8.1 recently came into my possession, I don't know if I should install windows 8.1 or or just use its verification key when win 10 officially releases. Thought?

I strongly advise against using beta products on daily drivers, and there are a number of tools that can make 8.1 entirely usable by getting rid of the touch UI.

Windows 10 is pretty stable at the moment. I'd stay with it

I guess the thing to do is to see if windows 10 does what you want, if it doesn't then try W8.1, if it works for you then why change? You'll have lots of experience to help other community members and those around you when the masses switch over!