This place was exactly what we wanted: a low-key off-strip mexican place with good food. The food & ambiance are what we wanted, and the price wasn't bad either. Regular "combos" going from 10-15 and specialties ranging from 15-20. We live in san diego so mexican food is something we're pretty darned familiar with.
I had a combo with flautas (which turned out to look more like a enchilada, i wasn't expecting it to be covered) and a taco. My wife had a tostada. The chips you could tell were made fresh, and the salsa was pretty good as well.
Service was very good.
If you're looking for a nice mexican place, then viva mercados is a good choice.