The Stand is simply incredible. As others have mentioned, it's much better than it looks from the outside.
As for food, their burgers are top notch quality--they're nearly every bit as good as you could get from a restaurant like Red Robin or Delux for half the price. In fact, the hamburger patty itself is more moist and delicious than those from most pricier places. I've never tried their shakes, but I've heard nothing but good reviews from others. Their peach lemonade (seasonal) was incredible and perfectly balanced, and their short rib tacos were superb (they were better than the short rib tacos from Chelsea's Kitchen). The only thing I'm not a fan of is their fries. They're very similar to In-N-Out's fries in cut, and they're probably just below In-N-Out's fry quality (which I don't care for to begin with).
The only other significant negative I can think of is their bathrooms. They're just outside the restaurant, and they aren't air conditioned.
Overall, I can't imagine giving The Stand less than five stars. The pros so dominantly outweigh the cons that the cons seem almost insignificant. If you're debating whether you should go there--go. If you're not considering going there--start considering...then go.