I'd read quite a few reviews and some negative comments, but I have to say that the Ruby Princess gets top marks in almost every category.
Check-In was very smooth.
We were booked on Traditional dining but because a number of our shore excursions ran into making us late for the early sitting, we were still welcomed at our table in DaVinci's when we could get there. The food was excellent and the staff went out of their way to make sure we were pleased. We had some senior ladies at our table and the waiter or assistant waiter even cut up the meat for one.
Our balcony stateroom was very clean and the steward friendly and attentive to our needs. The steward collected our passports after we were at sea, so there was no problem that had been mentioned in another review.
We tried Sabatini's and the Crown Grill and the food was delicious. Sabatini's artichoke souffle was outstanding.
The only complaints we had about the shore excursions were minor. One guide had a bit of a shrill voice. The region was having a heat wave and it seemed that every port had temperatures in the 90F range, so it made the walking to the buses seem long.
Disembarking at ports went smoothly.
Internet was (naturally) a bit slower than at home, but really not a problem.
There was usually entertainment in the Piazza and some of it was exceptionally good. There always seemed to be something of interest going on when we returned from our shore excursions (at every stop)
I would like to see smoking banned entirely from the casino, but maybe that's coming. We only went to one stage show and it was very good.
It helps to know that the hall carpet is bordered with red on one side of the ship and blue on the other side. I think that the curls in the wave pattern point to the front of the ship but am not sure so will check that out next cruise.
Lots of staterooms had balloons and a sign on their door...Happy Birthday or Happy Anniversary. Made it look festive.