I understand why you might be lured in. The food is cheap, they have those huge margaritas, and birthday-ers come out wearing a ridiculous sombrero. But the truth is, it's not worth it.
If you have a group going, you won't be able to make a reservation unless you're 20 people. You also won't be able to hear each other or even yourself. This place is incredibly noisy, since it packs in a lot of people who are trying to talk over the unnecessarily loud music. The best part of the meal is the chips and salsa you get for free as an appetizer. That salsa is like crack! After that, you get a very meh main course (though I do enjoy their salads, which are a good size and come in a tortilla bowl). Might as well get one of their big drinks to make it worthwhile.
I'd say if you're around here at lunchtime with a few friends, at least you'll get a cheap meal and it won't be as noisy. Otherwise, skip it.