I tried Windows 10 on both my desktop and tablet. I went back to Windows 8 on the tablet because the UI was horrible for tablet.

If anything, I think the pendulum swung back too much the other direction. There are a lot of UI decisions they made that make the experience with a tablet device painful. For example, the decision to get rid of the Charms Bar (in Tablet Mode) was a horrible one. A lot "Metro" apps don't really run full-screen anymore. Edge Browser isn't nearly as nice of an experience as full screen IE was (with the swipe gestures for page forward/back navigation).

On the desktop though, it has been quite nice to use...