This was our 5th cruise on Oceania, and it was as great as always. We were on the Baltic cruise and although we had been to a number of the ports there were some we hadn't visited. Since the ship is only in most ports a day, there is always something new we find to explore even though we have been in the port before.
There were only about 350 passengers (so we heard) on our cruise. Needless to say, there was never a wait at the buffet, Waves Grill, etc. I think we were only on an elevator with a couple twice. There was only a short wait for one to arrive after pressing the button to go up or down.
We were on the Concierge level, but I don't think it is necessary (cabins, bathrooms, bedrooms, etc. are the same) to pay the extra money if you don't need the Concierge service or you don't care about being closer to the upper level restaurants.
Very well laid out, very clean, wonderful toiletries, enough storage space unless one has over packed, very good supply of water and soft drinks, & the decor was very pleasant without being jarring as I have seen pictures of other cruise line staterooms.