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.
Three dance floors have been deleted.
The theatre, formerly decks 2-4, has been dropped one deck, to decks 1-3. The deck 1 lounge has been deleted, which is a serious concern for a group like Stardust.
Restaurant now has a Samsara open seating dining area, where the disco used to be. The disco is now decks 2-3. Dance floor deck 2 aft in front of the restaurant has been deleted (although there's a tiled area that can be used), bar area deck 3 aft reduced.
Lobby dance floor deleted, replaced by big hood ornament. You'll know what I mean when you see it. There was still a piano player, playing some decent music.
Restaurant seems to have a better layout, with enough room for waiters to move between tables. Menu was Costa standard, I always found something I liked and never went hungry, but you do have to watch opening times. There was a buffet some evenings.
Excite Piano Bar- Deck 3 bar midships (Florian on Atlantica). It does have a piano but is a regular lounge, capacity about 150. The dance floor is roughly semi-circular, 19' radius from stage. Rectangular area about 22' x 10', total area about double. The area is fully enclosed and non-smoking. There was a very good keyboard/singer duo, plus a violin duo.
Sharazad disco floor is 3' plexiglass panels, oval about 20' x 30'. DANGEROUS- raised 6"
Mirabilis lounge- Has a strong family resemblance to the Fortuna. The staircase is moved to the side, giving a more open feel. The dance floor has pillars, about 16' x 40' between pillars, 30' x 50' overall. The furniture does not crowd the floor as much as it appears on the Luminosa photo, you can dodge around the pillars quite easily. There was a 5-piece group plus a duo, both were very accommodating.
Cafeteria Sugar is actually the chocolate bar.
Stardust will probably use the deck 9 TV screen area for their private parties. I don't have a picture, I think the publicity photo is pretty accurate.
Smoking- There were at most 20 hard-core smokers, with maybe 200 casual ones. I never saw more people smoking at once than would fit into the cigar lounge. Smoking seems to be mostly banned in Western Europe now and a lot of people were shunning the smoking areas. The big problem was far too much space was designated as smoking area, far more than actually needed.