My two largest vices, designing UIs and creating new alts. Between the two, it is a wonder that I ever managed to get any of my characters to 70.
I have been hanging around on Moon Guard (RP-US) a bit lately with yet another priest alt. I took the opportunity to clear out the add-on folder and start over (again) from scratch. Fun, fun times.
Overall, I am satisfied with how the UI looks and functions. I may tweak a few things (minimap, buff display).