To pre-register on Costa website you need lots of patience. Their website is not very advanced. Boarding in Miami was easy. Ships was clean and neat. Lots of passengers get on at French Guadeloupe - so you have about 85% of the ship passengers as being Italian, French, German and Spanish.
Biggest complaint was the food service. If you did not eat at specific breakfast or lunch times, you missed out. Evening food was only dining room or $8 for a pizza dinner. No other food venue was available for the entire cruise. Water, juice, coffee, warm/cold milk and tea was available for breakfast. For lunch the available beverage was water, coffee or tea. Evening dinner was a nice selection on the menu. We were in late seating which started at 9pm. It was a long time from lunch until 9pm. Costa only served cold bread roll sandwiches each day from 4pm to 6pm.
Spoken english among the passengers was few in number. Staff did a good job keeping all nationalities of passengers happy. Shore excursions booked thru the ship were well planned. Evening entertainment was nice - very international in flavor.
Cabin was clean, well laid out. Could open door to get ocean breeze. View from room was a lifeboat.