For purposes of introduction, I've sailed on many lines including Celebrity, MSC, Pullmantur, Princess, Carnival, Norwegian, Royal Caribbean, and so on. I'd say Celebrity is my favorite cruise line, but I do look at price and book accordingly.
Health: In these Covid Times, the health protocols seemed pretty solid. This was a mask optional cruise, and I'd guess that 80% did not wear masks while 20% did. The passengers and crew were fully vaccinated. The ship was around half full or less, so enough passengers to make it fun, but not so many that distancing wasn't possible. The NYE party was pretty tightly bunched, but at least it was outdoors. I do have several videos posted of the cruise on YouTube. Maybe search for "Celebrity Summit New Year’s Eve cruise December 31, 2021 w/Celebrity CEO Lisa Lutoff-Perlo." on YouTube and then you can find the others, including a cabin review.
As mentioned, I did contract covid-19. I felt fine as I left the ship, felt fine on the flights home, started getting a mild cough a day or so later. Later, I got a notification on my phone of exposure from the California Health Dept. Took about 5 days for me to test positive (PCR and Antigen), after 3 negative tests. Fortunately, while I'm still testing positive 11 days or so later, I do feel pretty good and the covid I contracted resulted in very mild cold-like symptoms. A few have asked me if I'd do it again and my answer would be "yes". We had a really nice time despite the mild form of covid that I contracted.
We had a sweet 16 double-sized balcony and the room was in great condition with a good layout and we liked that extra balcony space.