A spotless ship with great service from cabin stewards to waitstaff. One exception: "Customer Service" is a misnomer. On three separate issues, I never received any satisfaction nor even an attempt to even lie to me!
Three other negatives, one especially impacts English (only) speakers. First, the food is basically tasteless and not very creative.
The breakfast buffet on Deck 9 is varied, but you could lubricate your family vehicles on undrained sausage/bacon fat.
Scrambled eggs ran (sometimes literally) from too soft to too hard. On two occasions, I left the dinner entree uneaten, including a piece of bone filled codfish. It was impossible to escape the smokers.
You cannot transit the ship without passing through the casino and large dance bar. You cannot use your balcony as the smoke drifts back from smokers not allowed to smoke in their cabins. Same problem often encountered in other outdoor areas. There is no segregation or walls/barriers for non-smokers.
The onshore tours were without exception bi-lingual. Guides do their best I'm sure but English speakers come up in last place, the attraction or point of interest already out of sight by the time they switch out of Italian, German or whatever. Many tours are entitled and shopping" but most often, there is insufficient time to shop. As for ports of call, they could do without Casablanca unless you're ready for new adventures in toilet facilities and systemic poverty.
One last observation: Americans are often labeled as "ugly". Observing the common courtesy of waiting your place in line is ignored.
Such scenarios are instead as orderly as an amphibious landing or frontal assault. I never heard "excuse me" or "pardon me" in any of the passenger tongues, given the cacophony of languages extant on the Luminosa. One also came away with the impression that Costa works their waitstaff overly hard. Many seem ready to look to get employment with other cruise lines.
The fatigue on many is obvious. Valencia, Malaga and Cadiz not on drop down list of ports. All charming.
Delightful. Take the Tram Tour
Equally enjoyable including and especially La Rambla