Locating Bruce Wayne in a penthouse at the center of Gotham work well with Dark Knights crime drama aspirations instead of being on the outskirts of town in a secluded manor, Bruce is smack dab in the center of the city but its also a nice nod to the 70s era of Batman comics. During that period, Bruce moved out of Wayne Manor after Dick Grayson left for college, and relocated himself to a sophisticated bachelor pad in the heart of Gotham, with a secondary Batcave hidden in a bunker under Wayne Tower. The comics Batman literally rebuilt the Batcave in exacting detail under Wayne Tower, stalactites and all; in the movie, Batmans secondary digs are a much more ultilitarian modernist garage.