Having had been on 10+ cruises before (Royal Caribbean, Carnival, Norwegian, MSC) I have to say that this cruise line is the worst when it comes to customer service. Travelers used to good customer service should not sail with Costa.
We sailed as a family for New Years 2018, and while we had a good vacation overall, it certainly was not due to the staff aboard the Costa Deliziosa. It felt like not only were they understaffed at all times, every day; but the staff was also grumpy - felt like they were just there to get the job done and get their paycheck.
While you can see the details of our experience below, overall, I would not want to sail Costa again, or would recommend it to any American friends, or anyone that expects decent customer service.
We had 3 balcony rooms. The members staying on 8341 and 7347, which are one above the other, really enjoyed the room as it was a big bigger than 7358 (normal size room).
7358 room was of average size, but don't be surprise if you get a call from 1980s asking for its style back, and also for its TV. The style of the rooms was a bit dated, and the TV was probably 10 inches. Very small. There is also only one outlet per room, so bring a power strip.