The Regal Princess is a beautiful new ship. The overall impression is outstanding. Definitely the nicest I've been on of six different ships. The architectural details - totally impressive - they spent serious money to make it top notch.
This is a very smooth riding ship. Most of the time you don't even realize it's moving along even when it was quite windy and the seas not velvet smooth. That was beneficial to my wife who is affected by the motion, she never even put on a patch this cruise. The cabins are extremely quiet, and the soundproofing is at a level I've never experienced on cruise ships, top marks for this also. Liked the flat screen tv with all kinds of on demand programming and live channels via satellite.
As many have mentioned it is a serious omission to not have stairways in the center section. At "rush hour" the elevators are totally packed and very slow, leading to many unhappy cruisers. I'd call this an annoyance rather than a deal breaker. But if I was running the show, I'd convert the crew stairways (which do exist) to public stairways via a little remodeling, and call it fixed.