I'm seeing a lot of complaints about service, but my experience with the drive-thru here has just about always been efficient and pleasant. (Of course, any task that ends in eating a hamburger probably gets graded on a curve for me.)
This is a good spot to pick up a quick lunch as you pass through the South Side...even if the dark pass-through where you grab your food kind of makes it feel like you're en route to a drug deal.