Is it intentional that you cannot right-click on a unit frame and use the "set focus" feature? Using the key-bindings works fine however. Other right-click functionality (e.g. setting raid icons) seems to work as well - it's just the set focus that doesn't work.
IMO the new UFs look great. I haven't had much time to play as much as I would have liked, but so far so good! Will provide more feedback once I have some more time.