Moscow to Kazan was the first of 7 trains we will be hopping on and off as we cross the length of Russia. The train that we rode from St.Petersburg to Russia does not count because the main Trans-Siberian route starts in Moscow and terminates in Vladivostok.
This was a "firm" train called "firmenny", which means that they are more comfortable (and more expensive). I was pleasantly surprised to find the train was absolutely spotless and thoroughly modern.
A video clip from the train which features Ivan - a little boy who Isaac became fast friends with.