I have had my fair share of tacos in Mexico and can confidently say that El Oso is pretty darn close.
(Nowadays) reasonably priced and my comfort food for gluten free (and dairy free if needed) quick meals. 3 tacos are enough for a small meal but my personal recommendation is to ask for extra tortillas, as the tacos are filled to the brink.
The Totopos nachos are a bit of a filler for me, so I'd skip that for an extra taco or 2 instead.
Even though there is usually a line, waiting times are reasonable. Absolutely recommended.