I'm actually impressed with this place, and I'm kicking myself for avoiding it all these years.
For me Cancun was always there along the route to go 'ol trusty Mexican joint Laredos. I thought it was just a crummy hole-in-the-wall knockoff. Instead, on an impulse to try it out, I've found a new 'ol trusty.
I think what I liked most was the quality of the food was superior to what you'd get at similar Mexican establishments. My tacos came in a corn tortilla and had a good taste that didn't seem like you were eating the equivalent of fast food. My wife even got nachos as a side dish to her similarly-good-quality burrito. Nachos!
So I'm happy to have found a solid Mexican establishment on this side of Madison.