We choose to try Ruby because of the lack of sea days. I enjoy going the islands more than the ships activities.
We stayed at Hyatt Place (Close to the port and parking is only $5 a day) the night before (eat at Gilbert's 17th Street Grill - Amazing burgers and service and in walking distance to the hotel). On a side note we did find it cheaper to take a taxi than the shuttle.
Boarding was slow due to a long line at noon. I really can't blame Princess; it seems the port doesn't have enough people (the people at the scanners were rude in my opinion) working with only 2 security lines holding up the lines. Princess could help by dropping the priority line which no one was using and the port officials occasionally sent others over. After we finally went through security; the princess officials were quick and courteous.
I did like how the cabins are ready when you board. We were able to drop off our carry on bag and relax on the balcony a bit. We met our steward at this point who did a great job with our room and always asked how my wife was doing because she suffered some sea sickness due to being pregnant. He offered some helpful suggestions which helped. Room D732 was an great room because we were able to enjoy an extra large deck without having to pay extra. I also liked how the decks are tiered. We were able to enjoy the sun without having to go fight for chairs by the pool and listen to music from our Iphones on a radio we brought. The negatives on the room were too low of a shower head for me and the pretty current movies were nice, but the TV selection was very very limited to news channels, love boat repeats and some ESPN besides the same movie being repeated over and over again. Lots of closet space was really nice.
As for ship activities we found the trivia games fun and LOVED the non smoking nights in the casino because of my wife's pregnancy and my allergies. The casino can get a little crowded in the evening and they were slow opening new tables. I figured they would want more opportunities to take peoples money though my wife and I did quite well ;-) The casino is small and sadly the poker table was pretty inactive except for tournaments. The illusionist, juggler and the comedian were entertaining though we only saw them in the main show room. A second show was done on the following night for each of them, but was done in the much smaller Explorer Bar and you couldn't get a seat unless you were very early. Hopefully they plan better for this on their newer ships. Along the same note they plans things in a nice looking Piazza area, but it's way too small as well. So many people you couldn't walk through at times. Piano was bar was entertaining in my opinion (just could be hard to hear because it opens to the Piazza).
The service was excellent at dinner. We had assigned dining time. The one thing I was they would do I take some time in planning seating. We were seated next to a nice older couple, but we had nothing in common with them. I don't know if it's just been dumb luck, but on other lines we've sat next to another couple about our age. As for the important part...the food. The food was good but uninspiring in my opinion in the main dining room. Some dishes were great and others were just so so. The same goes the deserts. The pizza and burgers on deck were good, not great. My major disappointment was in the buffet. Small selection in my opinion and if that wasn't your taste then it was pizza or hamburgers. Also they REALLY need drink machines. Service just isn't fast enough with the drinks or refills. Breakfast was also VERY boring. Only once or twice I found something I thought was unique. Having breakfast delivered to your room was hardly useful. They only offered an egg mcmuffin, fruit, sausage bacon and a drink (maybe cereal; i can't recall). No pancakes, waffles or even eggs. We did splurge one night and went to the Italian restaurant. Service was the best we received on the entire trip by the manager and server. The food was good and better than the main dining room.
The Islands. We didn't plan anything because of my wife's pregnacy. If she got sick we would lose our deposit, so we did everything on our own which saved quite a bit. Princess Cays is very relaxing. We rented a clam shell and unwind. Only issue was long lines to return to the ship so we just relaxed in the shade and waited for the line to go down. St Maarten is a great place, but five ships were in port so it was a bit chaotic. Taxi driver mislead us and we should have just trusted our instincts and went to places we wanted to go. Avoid the nude part of Orient Beach. Your memory will be scarred for life. Marigot is still one of my favorite places. St Thomas was nice. We went to Blackbeard's castle which has little to do with pirates, but the Rum Factory is great if you are into rum. I sampled a lot of rums and they boxed my purchase and sent it to the ship for me. Their prices are great as well!! Grand Turks is only nice in the cruise area. The service at Margaritaville was SLOW, but the food was good and the beach was nice. Many said going to town was a waste of time so we went back to the mostly empty ship and relaxed by the pool in back.
Leaving is always a sad day because you don't want to return to the real world. Princess' part is quick and easy. Again the port services fail. Long lines again to pass through security because lack of manpower. We took a cab back to hotel (with tip was $10 compared to shuttle which was $18 with tip and the cab was faster).
Sorry I am not very good at writing, but felt compelled after reading others reviews.
Positives: The entertainment brought on board, service at dinner and by the steward, large balcony, Smoking rules on board and Non smoking nights at the casino (LOVED THIS!!)
Negatives Uninspiring food, small venues and missed the mark on the little things
My personal rankings
Food: 1. Celebrity 2. Royal Carib 3. Carnival 4. Princess
Ship Layout: 1. Royal Carib 2. Celebrity 3. Carnival 4. Princess
Service: 1. Royal Carib 2. Princess 3. Carnival 4. Celebrity
Room Layout: 1. Princess 2. Celebrity 3. Royal Carib 4 Carnival
Next time it will be with a family; so we'll probably try Disney next.