It delivers, in my opinion, the best Mexican dining experience in Vienna.
The food is mostly authentic and any quibbles I have with the menu items are a matter of preference. For example, I prefer my guacamole to be very simple: lime, avacado and salt. Tacos Lopez adds onion. I can deal with that, because at least, unlike every other Mexican place besides Jalisco, they use real avacados instead of powder mixed into sour cream.
In short, this place is excellent. The service is friendly and the menu is diverse enough to feed any posse.
Menu items to try include the plato (some of everything), the mole tacos, the tampiquena, the gorditas with nopales (cactus), the guacamole and the wonderful beer-mixed-with-chilis and lime: mechelada!