Keep in mind taking a P&O ship is NOT the same as Princess. (yes I know they are the same company, but)The staff for P & O has a large amont of Indians and other staff from that part of the world. Also the food and menu's and how it is prepaired is much different than Princess. I am not putting down P & O, but to North Americans it is not the same product as Princess.
I have been on several "British" ships and enjoyed them, but many of the activities and food favorites are different than what you will find on ships sailing based in North America.
As long as you undestand P&O caters to different tastes than Princess you will be fine.