I have previously cruised with Princess and Norwegian and for me, the Pacific Adventure is better. It is comfortable, relaxed, priced right and the food is generally good, though the breakfast in the Pantry is ordinary. The entertainment is generally excellent. The Marque shows are top shelf.
Also tipping is included. Of course you are free to tip if you wish. I don't quite get it, that most other cruise lines don't appear to pay staff a decent wage. Passengers are expected to top up the staff's income. So much for the billion $ profits these cruise lines make and the sharing of it.
Some passengers expect the world for pennies. Caviar, crayfish, 5 centimetre aged eye fillet steak, etc., every meal. Spend a week in an inner Sydney hotel with 3 meals a day, travel and entertainment and you would struggle to do it for anywhere near the price that P&O charge.