I would not upgrade to Windows 10. It is spyware masquerading as an OS.
M$ has decided it can install anything it wants on your puter anytime it wants. Their attitude is, tough we now control you and your puters and there is nothing you can do about it.
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
Causing it to churn through data, blowing up usage caps
www.zdnet.com/article/windows-10-churning-through-bandwidth-blowing-data-caps/
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
If you do decide to update make a complete image of your hard drive in case you decide to go back to your original OS. We are finding using the go back feature built into Widows install is causing problem and M$ is deleting the recovery partition.