We took this cruise August, 2011(St. Petersburg to Moscow). First, let me say that I have only been on 2 ocean cruises prior to this Viking cruise and cruising is not my preferred vacation style. That being said, we were invited by dear friends to join them on this river cruise in Russia. I read the various trip reports and I am amazed how my opinion differs from many reviewers.
The ship I was on (Pakhomov) looks like it has been renamed in 2012 to Ingva. On other cruise lines there appear to be a variety of nationalities on board - but our ship was exclusively Americans. Given the way you are herded back and forth on buses - you could actually spend 13 days in Russia and never speak to anyone but an American (unless of course you get away from the ship/bus and make your own way - which we did).
My companions and I found the food barely tolerable. When in major cities (St. Petersburg and Moscow) we only ate breakfast on the ship. Although my expectations were low - they were not low enough and paying for our meals was the least of our issues.