This review covers three trips totaling 19 days, Adriatic/Aegean, November, but the experience was similar on all three trips. These were end-of-season trips, with a large number of new staff joining, before repositioning to South America. The ship holds about 3500 people, with only 5-10% being English-speakers. The English hostess said 25% is normal for high season.
I've only included detail on the items I particularly noticed.
SMOKING AND HEALTH FACILITIES:
There was a remarkable lack of smoking except in the casino, perhaps 100 hardcore smokers. It was rare to see more than a couple of people smoking at any one time. There was also a remarkable lack of grossly fat people, most people seemed to be quite health conscious. I was told at one point, there was a queue out the gym door to use the fitness equipment. My informant was astounded, neither he nor I had seen this before on any ship.
The ship was very clean and well maintained.
If your priority is wanton gluttony, then Costa is not a good choice, but generally the food was quite good, certainly for the price I paid. There were a few duds on the menu, but also some very nice dishes.
Breakfast and lunch buffets were perhaps not lavish, but quite decent. There were breaks in opening hours, so it was necessary to read the daily program. The buffet area was no more crowded than other large ships (I always avoid peak times, on any ship).
I found the main dining room to be comparable to at least a mid-level restaurant on land. I would expect to have paid at least 30 Euros for a comparable set menu meal. Service was not unduly slow by European standards, although there did seem to be a larger number of new staff than usual.
However, if you did not want a full restaurant meal in the evening, the only alternative was pizza.
I was able to sample the Samsara restaurant, which is a premium, open seating alternative to the main dining room (note that Costa uses the term "Samsara for several different things). A separate menu was offered, mostly superior to the restaurant, although there were fewer choices, notably salads. The main menu was available. Service and noise levels were difficult to assess as the area was almost empty.
I was booked in the smaller, upper/lower berth inside cabins. They are ample for one person. Europeans tend to prefer firmer mattresses than Americans, but otherwise, everything was entirely comparable to other ships I have been on.
I travel with Costa because of the nightlife, and was not disappointed. There are as many as 6 live music venues, with lots of choice of music. Some theme nights started as late as midnight, and the dance floor was packed. The Apollo lounge, the main lounge, has continuous music from 6 PM to 1 AM, except for bingo and (very popular) half-hour cruise staff games and entertainment. I don't like bachatta and can live without mazurka and Viennese waltz, but they were very popular. Although "ballroom dancing" when it was listed in the program just meant no theme, the groups, especially Duo Venus, were willing to play very nice dance music on request during quieter periods. The quartet did have the fault common to live groups of playing far too long- six minutes for a Viennese Waltz.
The rear lounge, Luna, has a much improved layout from the earlier Fortuna design, and offered various theme nights. The lobby bar is the equal of the main lounge on most ships. There are two additional lounges with live music, plus a keyboard player near the "Chocolate Bar" (it has a chocolate fountain). I did not particularly like the string trio, but their contract may finish soon.
The disco was not very popular. The DJ played the usual six-minute "dance mix" music, very boring and repetitious.
Given the small number of smokers on board, the designated smoking areas were far larger than required.
I did not go to any of the shows, but the comments I heard were generally positive.
The Serena has a retractable roof over the midships pool, unlike the earlier ships, which meant the area was quite tolerable even on cool days.
The hot tubs were not really hot. As nearly as I could discover, the temperature measured is that of the inflow water, not that of the water in the tub. They also closed quite early.
Costa tends to have shorter port stops than most cruise lines, but I've never been able to understand how an extra couple of hours makes much difference, visiting a city like Istanbul or Valetta. If I'm seriously interested in visiting some place, I'll go for several days.
Value was outstanding. Even using budget hotels and restaurants, I had a hard time meeting Costa's per-day cost on my land travels between trips. I believe I got the best value for my money I could have gotten, visiting this part of the world.