I love barrio. I'm a regular and this is my go-to place for tacos in Cleveland. That being said, I will say that dining experiences have varied. I've been there a lot, probably close to 20 times. If it's busy, good luck, there is virtually no where to stand and wait in the narrow bar area. Several times I have been seated in the bar area after waiting, and the other patrons are standing so close to your table they may as well join in on your conversation and meal.
If you can get a table on the restaurant side, good for you. The atmosphere is very casual and a good place to come for drinks (margaritas oh yes) and they have a nice variety of beers both on draft and bottle. The tacos, well, I'm obsessed. I do think it depends on what you get though, I recommend the shredded beef.
Servers have generally been very good.
Overall, go on a weeknight and avoid the mass chaos.