We chose Oceania because of its reputation, and the smaller size of ship which allowed a more port-intensive cruise (No "at-sea" days in the Baltic). We spent more money than we normally would and booked Oceania Suite 11080 - about 1,000 square feet at the back of the ship, with a wraparound balcony.
It was our first Oceania cruise after 3 Celebrity cruises + 3 river cruises (2 with Viking and 1 with Scenic). The first thing that struck us was the different approaches to handling your choices for alcohol programs, specialty dining, etc. There are pros & cons to all, and maybe they equalize in that way, although I got the sense that drinks on Oceania were more expensive than other cruise companies we have experienced.
Having 4 specialty restaurants to choose from at no extra cost, each either once or twice depending on your length of cruise and cabin class, was nice due to the variety. However, it does prevent the type of relationship building we experienced at Luminae on the 2 Celebrity cruises where we booked a suite. The service in all restaurants was very good, and the food was very good (except for the first night in Polo where both my wife and I had our steaks over-cooked. That did not happen again)
Furnishings were all of high quality - the bed and linens and pillows were excellent. The couch and chairs were a little low to the ground for our tastes. The extra media room would be nice if one occupant wants to watch TV while the other sleeps, but we never used that TV.
Our major "complaint" is the small size of the shower which we always use, while a massive amount of space is consumed by the tub, which we never use
We hired a private tour guide for the 3 days, which many others also did! I highly recommend this approach as it actually is less expensive than signing up for 4 or 5 Oceania excursions over that 3 days, and offers far more flexibility as to where and when and how long you see things
Tour was ok, but hard for some people to keep up and therefore miss a lot of what the guide is saying. Oceania needs to invest in tour communication devices!!!