My wife and I boarded the ship on Aug. 16, and stayed on her until Sept. 14. We do not do "formal," and chose "Anytime Dining," and ate in the buffet for the entire time except one night in the Crown Grill.
We could find nothing bad to say about the entire experience. I must say, reading the "down" reviews, that it seems people are really nit-picking. The food was fine, the coffee was good, and the service was outstanding. By simply being observant, we were able to see some really interesting things, such as a "Mola-Mola" sunfish on the surface near the Guernsey Islands, and a couple of whales near Iceland.
As far as the ship was concerned, our cabin was very comfortable, and our steward was always at our disposal. A couple of times the toilets briefly didn't work, and we were told it was because somebody nearby had clogged theirs by putting something in it they shouldn't have. The entire crew down to the "black gang" and deck hands were polite and cheerful.
The itinerary was fine - we saw a lot of places for the first time, and were charmed by Scotland and Ireland. It turned out that we retraced many of the steps of the Titanic, which I found fascinating. We did encounter a couple of storms, and the Captain made the right decision to stay in port at one point. We had 60 knot plus winds one night, but the ship was easily able to handle it.
When we got to New York, it was a bittersweet time, as we had made some fast friends among the crew. We were told that if we stayed on the ship any longer, we would be drafted as crew! Disembarkation was incredibly easy. We had a train to catch at Penn Station, and so disembarked at 8 AM. Much to my amazement, we were on the curb looking for a taxi by 8:15!
In summary, it was 28 days of great fun, and we plan to take more cruises in the future with Princess.