NO NO NO
I would not upgrade to Windows 10. It is spyware masquerading as an OS.
By default it logs just about everything you do.
http://boingboing.net/2015/08/03/windows-10-defaults-to-keylogg.html
http://www.zdnet.com/article/windows-10-silently-uses-your-bandwidth-to-send-updates-to-others/
http://bgr.com/2015/07/31/windows-10-upgrade-spying-how-to-opt-out/
They say you can opt out of it but it still phones home, it's a trap
http://www.extremetech.com/computing/212160-windows-10-still-phones-home-even-when-ordered-not-to-do-so
Then there is the matter of not being able to turn off auto updates or selecting what they install. In other words with Windows 10 M$ can install anything they want on your puter.
http://www.pcworld.com/article/2949621/windows/windows-10-will-force-automatic-updates-for-all-home-users.html
They have a bad track record with updates, but now it will get worse.
http://www.zdnet.com/article/windows-10-cumulative-update-causes-reboot-loop-havoc-for-some-users/
http://www.zdnet.com/microsoft-pulls-updates-recommends-uninstall-7000032678/
http://www.zdnet.com/article/has-microsoft-stopped-testing-their-updates/
I saved the worse for last The other reason for forcing updates on you is to also force new releases of the OS on you. They call it Windows as a service. This means the next time they have a Vista or Windows 8 you will not have a choice to update to it. They will use your auto update feature to force it down your throat. Everone knows the history of M$ and how bad they can be in detroying a good OS.
http://theconversation.com/the-pc-reaches-its-twilight-years-as-windows-10-becomes-the-last-major-upgrade-32411
http://www.itbusiness.ca/news/windows-10-review-the-last-os-youll-ever-have-to-install/58355