If you're happy with what you have, don't change. And beware of downloading it because it will then nag you incessantly to install it. You have 12 months (11 now) before you need to make a decision anyway.
Personally I'm far too unhappy about some of the security implications of W10 to change.
Edited to add:- if you use any older software or things like printers be cautious because drivers aren't available for many older pieces of kit so you could end up being unable to print or link to a camera or whatever.