Great place to have a great night.
I rather to go to the restaurants, especially "Guadalajara de noche" not exactly at the plaza, but 20 - 30 meters away, they have good show, not only mariachi, but also typical dances and great imitators of famous Mexican singers, Last week I went with my wife and stayed until they just push us out, almost 4:00 AM... The show wa really good.... Of course you can have dinner and take some tequilas....