30 years ago I worked at a DQ (and worked there p-t for 6 six years) and doing a nice looking curl was drilled into me. Whatever you're serving should look like the poster advertising the product. Because of this, I judge curls when I go to DQ. The curl is the symbol of DQ. Also, the soft serve in cones and sundaes should have the trademark shape (2 balls, NOT 1 big volcano). DQ has always tasted great and always will, but if my sundae is squat and smooshy, it's just not that special and looks like they don't care.
That being said, this DQ does a great job at the above. I've been to this DQ both when it's dead and busy, and the staff has always been friendly and as quick as possible. The place is always clean and has fun murals painted on the wall. They also have a twitter feed so you can be notified of specials.
Pros: Pleasant, efficient staff & treats that look & taste great
Cons: It's not close enough to my house