We chose this cruise because it is the easiest way to see St. Petersburg. If you book a shore excursion, you do not need to apply for a visa. Note that you do not necessarily need to book through the cruise line. There are other companies that are less expensive, and do a great job. We used SPB tours. I would recommend them.
As for the ship experience itself, there were high and low points. The staff on the ship is great! Everyone was friendly and very courteous. There were a LOT of people on this ship, and they seemed to handle the masses very well. For the most part, the embarkation and disembarkation went very smoothly. The only exception was St. Petersburg, but this was due to the customs process. I felt the ship handled this as best they could.
I found the food itself was only average. The 3 main complimentary restaurants shared the same menu, so it didn't matter which one you went to. On 2 occasions, we paid for a meal which was slightly better.
Small, (as expected) but, very smartly laid out. They made good use of the space, and we were comfortable.