In most cities, having to go to the post office engenders major bureaucracy-avoidance behavior. Do I really have to go down there? Find a parking space? Wait in line for an hour before an unhappy (and therefore, unpleasant) postal worker does what is laughingly called "wait" on me?
I just mailed my Christmas presents today. Deep in the heart of the Financial District, ten days before Christmas, at noon on a Friday: it took me less than ten minutes. Only two people preceded me in line and there were six service windows open. You do the math.
And I mean it when I call them service windows. (I more typically refer to such locales as disservice windows. I don't know what sort of happy juice they put into the workers' coffee at the San Francisco post offices, but that's how I want my tax dollars used. The woman who helped me was friendly, polite, even open to humor.
Even parking is, oddly, less of a problem than it is elsewhere. San Francisco actually has enough post offices that you can usually walk to one, thus obviating the need for parking. At least for my life: I have easy access to post offices both at home and at work. I admit that my home post office is less fully staffed and often has a line (especially near 4 pm). Since it's near the Haight, I also encounter some "interesting" characters in line. But they're harmless and sufficiently grateful for the shelter to be reasonably well-behaved.
So a very Merry Christmas to you from a most unexpected location: your nearby San Francisco Post Office.