I have been taking tours around the world for over 40 years, and I can say that Vadim is one of the best guides I have had around the world for several reasons.
Our first tour with him was for Art Nouveau and Cubist Architecture in Prague. But he was so good on that first tour that we arranged for him to give us another tour of the Prague Castle. My only sorrow is that we did not use him earlier in our trip to gain a fundamental understanding of Prague and the Czech republic from the outset.
Vadim is a unique guide because he has an amazing depth and breadth of knowledge across many topics, including art, architecture, history, politics, religion, culture, and sociology. He is able to magically and seamlessly weave all of these things together in a conversation. Consequently, you hear not only about art or architecture, but also the history of Prague (and Europe) across hundreds of years.
In his historical discussions, he tells you not only about the religious clashes underlying those events, but also the psychology driving different factions and decisions. Likewise, his discussion about art and architecture describe the historical and psychological context in which those different trends arose.
Finally, while he is very funny, he thankfully does not use canned, rehearsed jokes that many guides painfully use. Rather, his comments and jokes arise naturally in conversation, as he peppers his discussions with funny anecdotes across history.