Having sailed Royal Caribbean in the past, I feel the Serenade of the Seas is found to be lacking in a number of ways. Most of the issues are with the service. Although almost all of the crew I encountered were pleasant, the actual service was below RC standards. I saw my cabin attendant twice on an 8 day cruise. Delivery of clean glasses and bath products were sketchy. In the dining room, it appeared the waiters were overwhelmed and had too many tables to serve. The wine steward was nowhere to be seen most of the time. It didn't help that this appeared to be a "training" cruise for a lot of the crew. Also, the tables were so crowded together one could barely maneuver getting to your table.
I would say two of the nights had entertainment that would be considered quite good.