Huge line at lunch - but it moves fast. Check in on foursquare to get a free drink upgrade, and be sure to join their loyalty club. After you spend $100, you get a $10 on your card, and $10 on your birthday - I've been eating for free since September.
They offer the typical, tacos, burritos, nachos, taco salads. I always go with a two taco combo, soft taco, to go.