Hold Off and research this before upgrading. There is what may be very serious "chatter" around the InterWebz that there is really bad Privacy Intrusion Issues, like, where images/vids/documents get scanned by 10 and if certain keyword combinations or Image Hashes are found could lead to Law Enforcement kicking down your door at 3:55 AM in the morning.
Maybe its just more Internet Lies but it sounds "MicroSofty" this auto-scanning of files on the HD and this is inevitable, a matter of time before the NSA has such a deal in place with MS so please just everyone due your Due Diligence here and from here on out
where regards to anything that'd be capable of scanning your HDs then sikking LE on ya. We are as a group right now within a literal
Minefield considering the Blank Check powers given to NSA, FBI and especially those in combination with a software company to whom your privacy is of absolutely no concern beyond fooling you into believing its important to them so they can sell stuff.
And they are, to a large degree, not even selling this.....10.
The Free Upgrade and the intrusive insertion of that via normal Windows Update should tell you something.
Its not "just cuz Win 8 sucked so bad"
"Someone" wants WIN10 on America's computers. Why?
You're smart enough to figure out who that "someone" is and why.