After spending an hour with Win10 installed in a VM in VirtualBox let me report:
(1) The good: The annoying Metro tiles can be eliminated and I like the default wallpaper.
(2) The bad:
Firefox does not come installed so job one is to install it.
The windows have no resizing borders or handles which is quite odd.
All of the windows and widgets are a dull and flat in appearance. It’s very bleak.
The start menu is back, different from the useful one in Win7, and they stuck the metro tiles to it. Ugly.
The search icon in the task bar is a pure Bing tool, MSFT is so desperate to promote Bing they made it a forced default with no ability to change it, or even to remove it from the dock.
Now there is a control panel and a PC Settings panel just to confuse the user
On installation they try to trick you into using a Microsoft cloud account instead of a local one
There is this crazy notion of the Windows Store App - those full screen Metro things ??
A lot of windows open full screen for now apparent reason so you have to resize them. A Metro leftover I guess.
The menu bar at the top of most apps has disappeared, now its buttons and other weirdness.
(3) The ugly: Spyware that lets MSFT watch your every move including a keystroke logger that would make the NSA blush. It's hidden in the EULA that nobody reads.
So you can choose to believe or not that this kind of spyware will remain inside Windows 10 so that MSFT can continue to curry favor with NSA illegal domestic surveillance, or you can go open source and embrace Linux.