Just back from my first Costa (have done Cunard, Princess, HAL, RCCL, Carnival before). Deliziosa is a new ship and a such was in excellent condition.
Embarcation at Copenhagen was painfully slow. They had only 2 desks, manned by ship's dancers who only had to check name on embarcation form you carried with your passport. No computer terminal or even a printed list to tick names. Still took them for ever. I stood in a queue for 1 hr 25 mins. An elderly lady behind me fainted, and I'd be surprised if she was the only one that day. Costa Card (combined room key/on board charge card) was in the cabin.
Plenty of storage space in cabin, cabin steward excellent with high standards and desire to help when needed, cabin tv channels not good unless you speak Italian, French, German, Spanish. Only English-speaking channel was BBC World.
Good position in ship - away from lifts and didn't see a soul in corridor.
Plenty of storage space. Blackout curtain linings excellent (and necessary due to 24-hour daylight in northerly areas). Nice balcony furniture and plenty of room to stretch out on balcony. Only negative aspect of the balcony was that it on a stretch of cabins slight inset from others, which meant that I couldn't take photos along the side of the ship from the balcony, as the next stretch of balconies protruded into the pictures. The only sound from cabins on either side was of their cabin telephone, otherwise I wouldn't have known there was anyone in them.