My wife and I recently sailed on our 5th cruise with Princess Cruises. We decided to repeat the Eastern Caribbean itinerary because we wanted to sail on the new Royal Princess. Overall, we were had an awesome experience and noticed some changes that we really liked.
First, the Horizon Court had been upgraded and included more food options and easier access and flow. We would have been satisfied with eating here all week. They also added a dessert only room that is incredible.
Second, the piazza area is larger and even more beautiful if you can believe it. There is more entertainment and dining around the piazza that makes it a focus of the ship and easier to know what is going on and walk around and try different areas. Third, the rooms are nicer. Yes, our deluxe balcony was a little smaller, but it was nicer. So you need to consider that when knowing what's important to you. We didn't find the size uncomfortable and the lay out actually made it more comfortable.