My parents took my wife and I to Tia Rosa one night for dinner, and the line was so long we decided to return the next day for lunch. I'm glad we waited -- we were seated right away the next day, and it was quiet enough that we could enjoy the food and conversation! (It's just a hangup of mine -- I struggle to be heard in loud restaurants, and don't really enjoy shouting across the table, especially when my mouth is full of refried beans. I don't think the person sitting across the table from me enjoys it, either!)
I ordered the Flying Saucer which reminded me of a tostada all dressed up and tricked out -- it was delicious. I highly recommend it, although if you're hungry you'll probably want to order an appetizer or side. I also ordered a margarita with some magical combination of liqueurs -- I can't remember what was in it; only that it was tasty enough that my wife and I each had two! The dining area was extensively decorated for Christmas, and the service was prompt and professional, so everything came together for a truly enjoyable experience. I can't wait to go back next time I'm in town!