If you`re into gaming you`re going to need Windows 10 if you want to play games that use DX12. The only complaint I had with Windows 8.1 when I upgraded from 8 was that it wiped out my saved games I had playing Assassin's Creed 4 Black Flag, had to start all over from the beginning. I already have my copy of 10 reserved. If you`re not sure you need DX12 you may want to read this review.
http://www.eurogamer.net/articles/di...-a-gamechanger