Not a fan exactly, just prefer Princess to P&O.
Capacity of the new ships will be around 4400. The first, Sun Princess, sails next Spring. Prices are eye wateringly expensive at present.
As I won't be sailing in them any time soon, I haven't been paying too much attention to the details. But one thing that did strike me, was that there is a distinct move to a ship within a ship concept, with more expensive cabins getting private deck areas, restuarants etc.