I just did the Trans Siberian mostly solo and it was one of the best experiences I've ever had. Of course the best section for me was Novosibirsk-Irkutsk where I had three great friends of mine join me. They brought life to the experience. One thing is certain the further you get from Moscow the more you enter the Real Russia. I highly recommend the trip. Eventually I'll finish writing my trip report I promise. I have a lot to share.