Two stars might be a little low, but considering how many great taco shops inhabit this general neighborhood, was the best I could offer.
Everything was "meh", not bad. The tortillas were adequate, the fish fresh but flavorless. The toppings are ok, but even there the pickled veggies were uninspiring.
The toppings bar itself isn't a terrible idea, but it loses the thoughtful preparation of a good chef who knows flavors.
There are better places to go for fish tacos nearby.