We chose this cruise because of the three full days docked in st. Petersburg and we're not disappointed. Russia, especially Moscow (which we visited via the high speed train and spent about 8 hours in) was great. We did not use any Oceania tours, in Russia or anywhere else. Consequently, due to Russian visa requirements, we had to prepurchase a private tour. We used SPB Tours which was competitively priced and had excellent guides and drivers.
Embarkation was extremely easy. The shipped was docked right next to a suburban train station which we used and had some fun doing it. No line at all at check in. We walked directly to our cabin and had the safety drill and then dinner.
Some of the smaller ports such as Rostock and Klaipeda didn't have much to see, but were enjoyable just the same. We took walking tours in almost all cities (they can be found by going to the local tourist office).
We were upgraded to this cabin for a nominal fee. It was next to the elevator, but we did not hear anything all cruise. The concierge room was of marginal benefit: one night we watched a World Cup game on a big screen tv. Other than that just ate a few cookies and coffee.