"Remain words after removing the U" is not a solid word connection; it's almost as weak as "W appears as the second letter," which I saw in another puzzle on this site yesterday. It's a cheap shot, asking the solver to look for abstract properties rather than a tangible category. A good "word" category has a connection BEYOND asking the solver to do something arbitrary with the words, like remove a certain letter. For instance, in the most recent series (16) of Only Connect, this group was on a wall: August, Sacrament, Helen, Dove. Add one letter to the end of each of these, and you get a U.S. state capital. That's a tangible category -- once you do something to the words, there's an actual connection. "Remove the U from these four random words to get four new random words" is just B.S.

@Joshua, I respect the sentiment if not the delivery. I've since updated this puzzle with a new connection. I'd love to hear your thoughts on the change. Cheers.