If you're into authentic, a mexican friend of mine told me this is about as authentic as you can get. Me, I'm just another ignorant foodie that's content with the food-court Mexican food (a la Taco Bell, Taco Luis, Taco Don etc). Deep fried greasy goodness for the range of about $5-10 suits me fine, quick and easy as well, authenticity be damned. But once in a while, I do want something different, and when I'm on a health binge, I just can't handle some of of deep-fried stuff. Pepita's will give you just that. The atmosphere is a bit different and sometimes there's live entertainment as well.
The service at Pepita's is pretty good, the staff are pretty friendly. The food can take a while though sometimes....I guess I've been accustomed to instant food-court Mexican food. With the authenticity, you get food that's a bit more healthy, and a wider variety of food that hasn't seen a boiling vat of oil. I've been there a few times and the food tasted great, but I just can't justify paying $15 for a plate of beans and rice anymore. A lot of this stuff I can really make at home.