My family has sailed with Costa on 4 different ships. My daughter and I are going again March 13th (eastern carib.). We are so excited because of the 4 ships we've sailed the Atlantica is our favorite. All the Costa ships offer great service, food and fun times. What we like about the Atlantica is it is not too big (even during busy March break you can find places to be alone albeit indoors) and we love the full upper deck that allows you to walk around the whole ship. We take a brisk walk in the morning watching the ocean and sky (on "days at sea") or watch the fascinating docking procedures as we enter a port. Being sailors this is always interesting to us. After dinner in the evening and shows you'll find us taking a more leisurely stroll before bed time.
Hope you have a great time.