Please don't get me wrong on this, but being Mexican myself I think I should know good Mexican food when I taste it.
Cafe Pierpont's food is great actually, but to call it Mexican food speaks to the general lack of knowledge of the population of Salt Lake when it comes to ethnic food. Its not the Salt Lake citizens fault, they're victims of the homogeny of this State.
If the people of Salt Lake want to try authentic Mexican food drive over to Red Iguana, that is about as authentic as you can get for a sit down meal. If you just want to try a great tasting Mexican taco, drive over to Taqueria Piedras Negras, a hole in the wall for sure....but the real gems usually are found there.
Pros: Good food, Good Service, Good Selection
Cons: Not authentic Mexican, Can get very crowded, Pricey