On the first cruise we took all the entertainment was wonderful. Of course, it was all new. You're right--these theme nights are getting a bit boring. On the other hand I prfer them to the off-colour comedians that are so often there.
I must say, though, that the young group of dancers aboard the Constellation last Feb were awesome. Not only did they offer dance lessons to the passengers about 4 times during our 7 day excursion, a couple of them performed an amzing acrobatic routine for us. There was lots of energy there!