Note: this review was originally written in response to a query from a dance group sailing on Costa Luminosa, with comparisons to other ships we have sailed on. The photos referenced are not included.
From the deck plans, the Deliziosa and Luminosa should be very simlar.
The Atlantica/Mediterranea have same basic design, but the Fincantieri builds (which include Queen Victoria and Queen Elizabeth) have some important internal changes.