Travelled with Oceania before and enjoyed the experience. Regatta is a very elegant mid size ship, and on our cruise was full. Still has plenty of space, but breakfast area in the Tapas could get very busy at peak times. Food in all dining areas was real quality, I found it better by far than Silversea, and would go again for the food alone. Basic cruise price is reasonable, drinks are not cheap but if it helps them keep up the great standard they offer then I for one will not complain.
Various shore excursions however are overpriced and to be avoided. Found a company online that conducts tours in St Petersburg to merge with visiting cruise ships. They are called DenRus and we had a three day package with then that was fantastic, the literature that DenRus supplies is hilarious, highly recommended.
Our cabin was not very big but had loads of storage and was well equiped, vast number of DVD's available on board but no time on this engaging trip to see any! The weather for two weeks was stunning, 90% of the time just warm with blue skies, I never expected to be in the swimming pool in mid September in the Baltic. The ports of call well chosen and it was a great trip. Overall very happy with this ship and cruise line, would be better if they dumped the silly art auction, and not certain, but I think the cruise director was an android.