My wife and I just returned today (May 30, 2011) from a 10-day Alaskan cruise aboard the Sea Princess. This was our 10th Princess cruise. We have also cruised with Royal Caribbean and Carnival. Overall, we were disappointed.
1) The ship is getting a little long-of-tooth. For example, some shabbiness is apparent, and the internet cafe has such poor bandwidth that internet access is extremely slow and difficult. If you are paying for this service, you won't be happy.
2) Service gets worse with every Princess cruise we take. It's not that the staff doesn't work at it, but management sets the bar too low. The "Carnivalization" of Princess some years back started it all off. The automatic tip program encourages mediocrity, and has taken much of the incentive away from staff to "go the extra mile". Unreplenished tissue and missing towels were repeatedly a problem; personal property was damaged through carelessness.