Not a lot of choices in Madison for Mexican food and given that most Mexican food restaurants in the state choose to "dumb-down" the authentic spices to adjust for the mid-west taste bud.... there may not be - except for those who choose to stay totally genuine to the cuisine.
Wife and I decided to stop in on a recent trip to Madison - and while e enjoyed our evening - it was not authentic in the flavor area. The food was well prepared - it just lacked authentic spices to the level that this California-born, Mexican food lover couple prefer.
Service was goos - we were well attended to and asked for a specific area in which to sit and were pleasantly directed there. Price was more than fair and for the value, felt like it was a good meal.
Others may rate it higher - and if we did not prefer more "kick" in our food - we might have rated them higher too. the place was clean, well staffed and was busy with lots of folks who were enjoying themselves.
So... if you prefer miler mexican food - this place will suit your needs but if you want more authentic - you may want to request the spicier dishes on the menu to get something more in tune with the typical authentic mexican faire.