Uber, I dont think its so much Windows 8.1, I think your problem lies with buying off Ebay and buying a $295 laptop. The cheaper you go, the worst it gets.
I've had a Win 7 desktop for over 5 years now, and I've had my surface pro 2 over a year now. My SP2 runs as smooth as the day I got it and my desktop does too. Its to each their own and I think everyone who buys a device from a phone to a computer will each have different problems.