At first I was hesitant in upgrading from Win 7 to Win 10. I had tweaked 7 to my liking and it ran everything I wanted.
I decided to at least try 10, after backing up my boot partition and downloading the ISO of the Win 10 install. Well, after being a bit confused by the newer options and layout I find 10 to be well worth the change-over. There is one app suite 10 refuses to run, at least on my upgraded system vs. a fresh install route. PowerDVD 10 OEM I received when I bought my BD-RW PC drive.
At first release there were several "ooops" with 10 such as NOT having drag-n-drop app support, but the latest version does bring back that critical feature I use all the time. Another "oops" was that on some upgraded systems 10 refused to recognize CD/DVD drives. There was an easy fix easily found on the internet. I do not know if the latest version fixes that.
There was also ZERO support for desktop themes, something I was really peeved about. That support is back, including the "glass" look.
At first the "flat" window look was a bit annoying, I liked the rounded windows widget look of 7. After several month of mashing and tweaking 10 to my liking I find the flat window look actually easier for these tired old eyes to deal with.
One older desktop app I run still popup child windows with the 7 look. Sure is strange to see a main 10 looking window with retro child windows.
Having Win 10 Home keeps one VERY annoying feature, automatic updates. I don't have the desire or money to upgrade to a pro version, so I will put up with that.
Overall upgrading from 7 to 10 works just fine for me because I try to keep a clean system without adding a lot of crud junk as most people do.