First of all, I know what Carlos O'Brien's is. It's an Americanized Mexican place with chimichangas and such. Being in town visiting family, someone chose this place for a group dinner. It wasn't me. I vaguely remembered liking it as a child and ignored the Yelp reviews. The menu was typical Arizona Mexican food (the Carlos) and "pub" food (the O'Brien) I had no expectation of authenticity or gourmet ingredients.
The space is huge and it was fairly busy but not packed. The decor is straight out of 1980, which actually was a bit charming. Our server was personable and did a great job. The food was TERRIBLE. I mean really awful. The hot salsa tasted of nothing but ground chiles and the mild salsa was worse than bottled grocery store stuff and just tasted like sugar and tomatoes. The chips were good, but with nothing good to put on them it didn't really matter. My food was beyond bland, and everyone agreed. We dumped the hot salsa on everything to even make it palatable. I think we had a total of eight different dishes and nobody liked any of them except the cheese crisp (and one person didn't even like that). My margarita was terrible, tasted like straight from the plastic bottle margarita mix and had very little alcohol and almost no salt. There is no way I would come here again or recommend it to anyone.