A friend of mine was on the phone with the DMV at work. At one point he said something like "If I did my job as poorly as you do yours, I'd be down there at the DMV working with you."
Anyway, in my experience DMV employees are often surly. On the other hand, the people who work at my local post office are surprisingly polite. Perhaps they realize I can always go to Fed Ex or UPS to get stuff mailed.
The DMV doesn't seem to be particularly concerned with customer satisfaction...after all, it's not like they have competition. If the PA DMV sucks, it's not like I'm going to take my "business" to New Jersey.