I installed 10 on a laptop. When setting up it gives an option to opt out of auto update. But... auto updates anyway. What scares me is that I learned long ago not to install most optional updates. Video drivers usually don't work. Lan drivers usually don't work. For the lan, you have to dig out the mobo software and reinstall it. Then get on line to get video drivers. Not fun.
As far as the 8 metro screen. How is it, after all this time, no one seems to know how or even that you can shut it off. I didn't like it. I disabled it. The only thing 8 screwed up, IMO, is the start menu. Which classic start fixed. Of course, 10... removed it. So here we go again.