We just got back from doing the absolutely delightful UNIWORLD Imperial Waterways of Russia river cruise. What a wonderful experience.
We did the cruise the last two weeks of July via the Moscow to St. Petersburg option, versus the reverse. I highly recommend this option because Domodedovo Airport (IATA code DME), serving Moscow is south of Moscow and right at two hours from the Severniy River Port, which is up on the north side of Moscow.
Whereas, the Pulkovo Airport (IATA code LED), which serves St. Pete is only 30 minutes from the St. Petersburg river port, both being on the south side of town. We left our boat at 3:30 am for our 5:55 am flight on Lufthansa out of St. Petersburg to go to Frankfurt. You would probably have to leave the boat around 2 am to go to the airport if your were flying out of Moscow.
The River Victoria is a wonderful, modern vessel. Very, very nice, It appeared to have been through refurbishment recently. The verandah stateroom we had was standard riverboat size, ie large enough, very modern and well furnished. The beds were just right for sleeping after a days worth of adventures. The ship's elevator is modern, and very responsive. The decor throughout the ship is beautiful. The gift shop had a great variety of beautiful gifts if you could not find enough stuff ashore to buy. The wi-fi service was good throughout the cruise.