I've been using it since the day I started this thread and I'm pretty impressed. My PC isn't very good, but Win10 runs flawlessly. I like the new features like the new alt+tab window (if you hold alt+tab you can close the windows you want in it), the big notification that it uses instead of the balloon tip notification for items in the taskbar and the new snap-to option - if you drag a window to a border it snaps there (that's nothing new) BUT it shows every other window on the empty space, and you if you click one it fills the empty space with that window.
So far it's been a good experience. My only problem now is that I've just ordered a new motherboard that apparently has no drivers for Win 8.1.... Hopefully I won't have to roll back to Win 7 or something. ):