Just my opinion here. But why do you think Windows 10 is free and you still have to pay for Windows 7?

Windows 10 contains a fair amount of spyware that sends info about you back to MicroSoft.

If you are on 7 and it's working for you, I do not recommend an upgrade unless there is a feature in 10 you really need or must have. But then, I would still add "O&O Shutup" to kill the spying and "Classic Shell" to give me a familiar interface. Still not as good as 7, though.