We just got off the Regal Yesterday. This was our 8th cruise with Princess. Our 1st was back in the late 90's. My wife and have sailed on over 30 cruises with different lines.
Pros: The new ship is beautiful, its clean and well decorated. The crew has a very friendly positive attitude and always smiling. The cruise staff is very active. There are games, trivia and things to do all day long. We didn't have much down time. The production shows were awesome and guest entertainers were very good. The best is the design of the buffet on deck 16. It never seemed crowded. Silverware and napkins are on the table and your drinks are brought to you.
We cruised on Princess back in November on an older ship and didn't have good time. That ship was old and run down, so was the crew. This was a make it or break it Princess. Well Princess redeemed themselves with our cruise on the Regal.
Cabin - M617 top of the line balcony is small, the balcony is very small (smallest we have ever had). There are two chairs and a round table. If the back of the chair is against the sliding glass door your knees almost touch the glass on the balcony railing. The shower design seems to have more room but two people can't stand in the bathroom. The bathroom lighting doesn't seem to be a bright as other cruise ships. We also talked to a couple who had a mini-suite, they had the same amount of room (tiny balcony).
Ladies - The makeup desk doesn't have a pull out drawer. Its on top of the refrigerator.
With only one ship at the island, it's very crowded. Very long lines for any type of food. No hand sanitizers anywhere on the island. When you tender in, go to the right it is less crowded.