If a person is not into nightlife or the fashion scene and doesn't need to make any business connections AND would like to save some money, then there is no particular advantage to staying in Shinjuku or Shibuya. Both are crowded, confusing, noisy, and short on attractions that might be considered "typically Japanese."

The northern part of the Yamanote Line is quieter, cheaper, and more likely to give the visitor a look at what life is like for typical middle class residents of Tokyo.