A day later, we are still talking about this meal! Easily the best mexican food we have ever had (and we have eaten a lot all over the US), and probably one of the best meals I've eaten ever. We ate lengua (beef tongue) tacos and cheese enchiladas and guacamole... I don't even know what the flavorings were, but everything melted in the mouth. Just superb. Cannot recommend this place enough, and we will be back if we come through Madison again.
Food came out in less than 10 minutes, so that's also a plus. Very friendly folks.