I've been to Barrio twice so far. Once with my girlfriend on a late Tuesday night. Everything was excellent, from the food to the friendly staff. There were only a half-dozen other couples and small groups, so it was quiet. I especially liked the build-you-own taco sheets and the long beer list. We were excited to come back, and surprised to find they're open late 7 days a week.
The second time was a Thursday, maybe 7-9pm, and we had a group of 5-6. It was pretty noisy and crowded, not that I can really blame them for drawing business. The tables all seemed to be set up for groups of 4 so we had to cram, and keep menus and unnecessary items on the floor. Fortunately the service was still prompt and friendly and the food was great. We split some salmon guacamole before the tacos and it was tasty and looked good too.
I made sure to try a variety of taco ingredients and liked them all! There are maybe 7 meat choices including pulled pork, chorizo, and fish. Careful with the salsas and sauces if you're sensitive to capsaicin ;) The chipotle crema and chipotle honey are tasty but not short on heat. Others are even hotter.
My biggest disappointment would probably be that beers are all served in mason jars and all kind of tasted the same. I guess it's fine if you love IPA exclusively but for a long list I expected more variety and proper glassware. Or lower prices... beers were all $1-2 more than I'm used to paying.
I think on both visits my tab came to ~$30. That's with 3 tacos and 2-3 beers.
Overall I was quite happy (esp. with the food and service) and will definitely go back... probably with a smaller group, late or on a Sunday night when most other places are closed.