I really like Rubios. No, actually, I LOVE fish tacos from Rubios. A long time ago, I lived in San Diego where I discovered what sounded odd is an incredible dish.
That said, I think Rubios has become a franchise and this you are not assured if getting the original quality at every shop. The Menlo Park location is good but *really* inconsistent. I've had top notch tacos. I've had them on the wrong tortillas (Corn instead of flour). I've had them still cold in the middle.
Again, Rubios is great and you should give it a try. Just know that a bad experience here is not representative of what you get at other locations.