My wife and I have been on four Oceania cruises on the smaller ships. My first impression of the Marina was that this is a large floating Vegas hotel. I learned to love the ship as the cruise progressed.
The embarkation was efficient. We arrived at noon and we were having lunch at 12:30 PM. Our room wasn't ready until 3 PM. There is a class system on this ship. People in higher category rooms have their rooms prepared first. They also get first choice of restaurant reservations.
The layout of the Marina is very similar to the smaller ships. Oceania has tried to keep most things the same as on the smaller ships. The food is very good and in most cases excellent. I had an excellent fillet in Polo, an excellent osso buco in Tuscana and an excellent meso seared sea bass in Red Ginger. The service is very good. The beds are great.
Oceania has corrected some of the problems with the smaller ships. The bathrooms are bigger and better. I liked having four specialty restaurants. The elevators are great. The lounge is much better. The entertainment is better but don't expect much.
I didn't take any of the ships excursions. They were very expensive. I booked a 2 day deluxe tour of Saint Petersburg with SPb tours. I was very happy with their tour which was very reasonably priced. The ship provided a shuttle service in Helsinki and Tallin. The port provided a shuttle in Gdynia. We got a taxis in Gdynia and saw Gdansk and the Stutthof concentration camp. We walked off the ship tp see Riga, Ronne and Warnemunde. We missed the stop at Visby. The sea was too rough for safe tender operations.
The internet seemed expensive.
There was a long wait for a taxis in Copenhagen.
My only major disappointment was the weather. It was far colder and wetter than I had expected. We had several cloudy days and a full day of rain in Saint Petersburg.