I think it runs fantastically. I've had no major problems, and honestly the only minor problems I've had are ones I've experienced on other OS's before, particularly occurring very shortly after installation. Once you've run it through its paces, it's good to go.
I don't concern myself with privacy problems because, well, I don't think I'm that interesting enough to watch x3 And I was say it's probably the fastest OS yet. Anyone claiming they experienced any sort of "slow down", well it's probably their machine or something they don't have set up right. Granted no two Os installations are guaranteed to be the same but, I've installed 10 on 7 machines so far, including three desktops in my apartment and on my Surface 3.