The tour was rather too short and not much to see and spend an entire day. There could have been more information about the tour, based on which one can decide, whether or not to go for it. Viator uses the airport pick-up bus between Vienna and Bratislava for the transport, which sounded quite uneasy. You dont get to know when to get down, since its a bus with continuous stops for picking/dropping passengers bound for airport. However, the guide was quite knowledgeable about Bratislava and its history. The lunch was quite ok also.
the big map provided was utterly useless. Please improve the content of the map or link the important places with corresponding metro /other public transport connections in a separate sheet (the guide book was partly useful). I spent a lot of time to figure out how to reach a specific place by just looking at the big map but was clueless on how to use the map!