It finally arrived - loaded it on my windows 7 laptop, frankly because I don't like 7 (prefer 8, would really like it if there was a classic XP look and feel of course!). And since its the secondary machine, if the 10 install made it a toaster, it would be useful to put a linux distro on (and it may get that eventually).
!0 does not seem much faster than 7, this cheap Dell only has a dual core and I'd hoped for a bit more speed. Applications still take an age to load from initial click - but then run OK. Thats probably down to the measly 3MB of RAM on it.
The upgrade kept all my applications, So I could go straight back to firefox - tried the £edge£ browser, and that did not impress me much. It seems to be set up to not take cookies from reputable sites. So go to BBC news page, get nag about cookies, go elsewhere, return - and nagged again for the BBC news cookie. So I'll stick to Firefox.
I had a test install of WW2, which was in full-screen mode. That launched happily. I then alt-tabbed out of it and back, and it had resized to a weird vertical letterbox size. And the font was nuked as well. Which is what it did in 7 with the installed drivers, so no change. Alt-tab and killed that.
Then used the gameoptions launcher to set to windowed mode at desktop resolution and hit start. Game options cloeed and
Nothing happened. Brought up task manager, no sign of the task. I tried a few things like running the programme directly, still no start. Eventually I
restarted the laptop - and then it launched happily from gameoptions as if nothing had happened. Maybe W10 keeps a "naughty boys" list of things you killed off?. Weird.
Absolutely no hiccups scrolling round the map, or when moving units about. In fact, it may be a wee bit faster than under 7, so I may increase the unit move delay.
MBT on the same machine in windowed mode also worked flawlessly.
The game borders fit right to the cheapo 1366 wide screen on the laptop, no desktop pixels left uncovered.
Windows 10 is really a warmed-over version of 8.1. Those like me that prefer an XP type classic start menu will of course download a start menu replacement - start8 or similar. Then you have a proper hierarchical program files list, and no more kindergarten tile stuff. (I replaced Microsoft's one within 10 minutes of downloading

!).