My wife and I have visited most of the Mexican restaurants in town, and this is among the top 5. The staff have always been friendly, even when it's extremely busy. The food is great.
The only real concern is that there tend to be a lot of flies flying around, particularly during the warmer months. I guess flies are just part of living here, but I wish the restaurant had a way to keep them away from customers and their food.
But, again, that said, this is a great restaurant and we will continue to enjoy food from Little Sombrero.