We chose Oceania because of friends recommendations. We have been on over a dozen other cruise ships and this was by far the most disappointing experience.
For a concierge level room compared to similar class on other ships, this was well below average. The concierge lounge was sparse and the appetizers snacks were the same every day.
The worst experiences were found in the shore excursions. Fortunately, we had booked private tours for key ports (Rio, Buenos Aires, and Sao Paulo). The ones from Oceania were all subpar.