Ironically, most Koreans I've seen hate the new (America-like) street number system. The problem is that these streets are either (1) really long (say, five kilometers, which covers a lot in a dense city) or (2) one of the several hundred small lanes that branches off these long roads, all named like "XXX street 138-lane"

In the previous system, at least the address tells you which township ("dong") it belongs to, which is usually a walkable distance. (So, for example, you'd have a pretty good idea which subway station to use.) In the new system, it could be anywhere along a busy street running through several districts.