Without addressing M'ville specifically, I'd like to address one of your points. Fast speeds don't automatically equal good racing, and slow speeds don't mean bad racing.
Now as to Martinsville: what appeals to me about M'ville is that it offers COMPETITIVE racing. The small size makes it impossible to a driver to get away from traffic. He's always having to plan ahead regarding the best place to get around slower cars without giving up anything to the cars behind him. The traffic also makes it difficult for a driver to get away from those cars behind him; the traffic does a good job of keeping the field bunched up without using artificial tools like shot clocks or cautions that may appear questionable; there's no driving around logging laps liek there is at some of the larger tracks. The narrow track makes it more difficult to make passes than at a wider track like Michigan; drivers have to work to get by someone. I enjoy watching someone have to work for several laps to set up a pass. Crew chiefs are challenged by pit stop schedules, since pitting under green is guaranteed to cost you at least two laps. Even that's fun; I like watching a car on new tires slice through the field even if he is a couple of laps down. The lower speeds allow cars to be competitive that may not have the speed to keep up at a faster track. That gives a chance for good drivers in inferior cars a chance to show their talent. And I'll admit that the single line means more 'bump and run' action and even wrecks, at speeds that are highly unlikely to result in serious injury. Plus, that grandfather clock trophy is way cool.
In short, M'ville is one of those tracks that places more emphasis on the driver's skills and less on the car.
The rest of y'all: quit gaping and answer his question.
EDITED: but the famous hot dogs are grossly overrated; emphasis on 'gross'.