After double-checking the Twisted Root site, I discovered that they are not open weeknights except Thursday and Friday. I purchased two burgers, fries, and shakes over the phone and drove over. There were many a rock-show-goer gathered on the sidewalk out front but plenty of spaces in the car lot next door. There weren't any shows next door, and these folks were just milling about. Don't know what that was all about, but hey it's Deep Ellum.
Got the food back home, but no fries! Honest mistake I suppose. Burgers were rather tasty - I'm deducing it was all in the meat, although the sesame-seed bun was quite delicious. Shakes made from homemade ice cream is a bonus. Would have liked those curly fries though.
On the whole, I'm very glad that there is a tasty burger location nearby. My wife says we can even walk there when the sun is shining. Don't walk there at night because people want to kill you.