When travelling abroad I am at the mercy of public transportation. Fortunately, that hasnt been much of an issue in places like Tokyo. In many places, the most efficient way to get around is via the subway. Subways dont have to deal with the road traffic and delays that can occur throughout the day. They are great but as a traveller, they do have some shortcomings. Primarily, you dont really get to see the place that you are visiting and theres a certain sense of disconnection with the places that you go to. Given that you are underground, you are unaware of what it is that is going by above you. Sure, you might some idea from a transit map. Above ground transportation is a cheap form of a guided tour. You get to take in more of where you are visiting by seeing all the places in between the sites you plan to visit. A benefit of that is you may come across something unexpected that catches your eye.
Secondly, when I arrive at my destination, I sometimes have to ask myself, "Where am I?" Of course I know where I am, but I ask this question in respect to how far have I travelled, which direction did I come from, or even where is my next destinaion. Using the subway, the city is a fragmented memory of locations with no sense of cohesion, no sense of the city as a whole. As I plan my trip for Seoul, I feel that is how things are going to be. Ive read the bus system can be confusing and does not print the stops in english. I havent travelled on the buses in Tokyo but the JR train lines are above ground and it affords me the opportunity to take in the city as I go.