My personal opinion would be no.

Reasons for yes:
-DX12 (But it probably won't come to life for at least 2 years if not more so no point for upgrading for DX only)
-Using less resources (About 5% less than Windows 8.1 if that's something you're pesky about)
-Option to record gameplay and synchronization with Xbox (You can record your gameplay like with Fraps with integrated recorder and also some games will be able to be played on PC and Xbox)
-Some other API non sense that mean nothing to yuo

Cons:
-Many people are still reporting many software related issues such as driver crashes and program incompatibility so if you are a person that uses specific programs for specific tasks such as Photoshop or like Sony Vegas I'd advise you to stay at what ever system you're at right now as you have a chance of making everything not working correctly
-Even less privacy than on previous Windows
-Above issue

All in all it is your decision that is final but unless you have an itch for latest OS I'd advise you to stay at Windows 8.1 for 2 years as by then they'll probably fix the issues that are present. You'll see a lot of people saying everything is fine and why to upgrade but as I said. It's your decision that's final.