I am originally from Tucson, and this is easily my favorite Mexican restaurant. While I still believe that the Tucson locations are better, this is still a pretty good representation.
I must warn everyone that this is NOT Sonoran-style mexican food, nor is it anything close to Tex-Mex. This is Mexico City style cuisine, which is something that is hard to come by this far north. Do yourself a favor and try something other than the dishes you are used to. The mixed grill is a favorite (#39), as is the chicken melt (#34), and the pechuga suiza (like a chicken quesadilla) is to die for (#32). My all-time favorite dish though is a combination plate, with two tacos and the pechuga suiza (#15). The tortilla soup is also very good.
One problem that I have come across with this location is the service. Multiple times I have been sat by the hostess and failed to be greeted by a server for 10-15 mins.
Other than that, I love this restaurant. I grew up eating at the Tucson location, and it was the first place I would want to go to when I would come home from college during holidays.