To me, the best part about the game is walking into a new city for the first time and having a look around.
If there are nine cities (five major and four minor), and I visit a new one only every three (real life) days, that would mean it'd be about a month before I saw all the cities the game had to offer.
Of course, in the meantime, I could still be doing quests and other stuff in the cities I had already visited. And even after I see all of the cities, I know I still have all of the wilderness to explore!