The ship looks great. My parents went on this same boat back in September and it really needed updating. They said the carpets and linens really needed changing. The carpets now look great and linens are very nice. There was no vibration at all on the ship. It is kept very clean.
Regarding the shore excursion in Cozumel and Calica, we did our own thing. In Cozumel we left to go to Chankanaad Beach. Took a taxi ($10.00) and got there before any crowds. It cost $10.00 each to get in. The fins, goggles and snorkle cost us $6.00 to rent. The snorkling was great. Many fish. They also have a small swimming area that is real nice. They have food there and drinks (try the "pineapple man") and a wonderful walk throught garden that is the prettest I've ever seen. We left there about 1:00pm and took a taxi to town.($10.00) Shop there for a while and ate at Pancho's Backyard. YUMMY! Walked about 3 blocks away from the strip to buy Vanilla. It cost us 1.82 a liter. Took a cab back to the ship ($10.00) and unloaded and ate dinner. Then we walked back to the pier to Fat Tuesday for the evening. Love that place.
In Calica we took the free Carnival bus to Playa Del Carmen to a little market. Did a little shopping there. Then ended up at Senor Frogs. We did not know at that time that they have many free beaches in town. One right off of Senor Frogs. We would have went swimming had we known that. We took a cab back to the ship ($10.00). Regarding the shopping, we did haggle on the prices and pretty much got what we wanted. Taxi's are everywhere and some do drive a little crazy.
If there are any more questions I can help you with I would be glad to answer them for you. Is this your first cruise? What room are you booked in?