This was the first Baltic area cruise for the Royal Princess and in every port we heard that we were the largest cruise ship to ever arrive there. In my opinion, the ship was too large with over 3,500 passengers. If large groups is your thing, the Royal Princess is your ship.
My wife and I felt the food was not as good as other cruise lines though the Horizon buffet was better. After a while, we stopped eating in the main dinning rooms and opted for the buffet instead. This was a major change for us since we both hate buffets as a rule. The two specialty restaurants were a huge disappointment (at $20 per person extra). They had no atmosphere and the food was inferior to the dinning rooms and buffet. The steak house wasn't even a separate room but a section of the Wheelhouse Bar.
On the plus side, the staff was outstanding and our balcony stateroom was always clean and neat. Over 26 days, we did develop a close relationship with some of the wait staff in the Wheelhouse Bar which added to our enjoyment. We like to find a nice place to have an afternoon drink and like to talk with the staff. I agree with other comments that the rooms were smaller than on other ships we had cruised in (Norwegian, Royal Caribbean, and Celebrity). I prefer tipping myself and rather resent the gratuity being added. We tend to increase the bar tip from 15% to 20% so we are not cheap tippers by any means. Since the $11.50 per person is shared, I did tip the room steward a little extra for his outstanding service.
We aren't into the formal scene and hate to dress up or have to pack formal clothes. Also, the food on most formal nights was nothing special, especially compared to Celebrity. We actually prefer the more laid back NCL. But, again, that is just our preference and other passengers seem to like playing dress-up.
Like most cruise ships, excursions ashore can get very expensive. If you are a first time cruiser, look into excursions on-line or do the research and maybe go ashore on your own. Most Baltic ports are friendly, local transportation is good, and most speak English. The exception is St. Petersburg since the Russians require a visa unless you are on a guided tour. I found a good tour on-line that had a group of only 14 passengers that was very good. We ended up spending about $2,800 more than the cruise cost which is "par for the course".
Would I cruise Princess again? Probably not because it just isn't a good fit for us. We did meet many people on board who had more than a dozen cruises on Princess ships. One had over 1,000 days of Princess cruising. It is just a matter of personal preference but I am glad we at least tried Princess.