I visited Esperpento last night, because a friend who loves the place and recently moved back to the area requested it. I thought it was worth a post because it confirmed my impressions of the place, which I haven't visited in several years.
Overall, I found everything acceptable but nothing particularly shined. The fried calamari were actually to be avoided, with a bland batter and odd almost undercooked texture. The accompanying alioli was a very basic. The anchovy-stuffed olives were identical to what I buy canned for cocktail munchies, which is to say I like them but find it odd to pay for them as a dish. The escalivada was served hot, which I've never had before (including my Spanish grandmother's version), but had good flavor. The artichokes were tasty, but hadn't been well trimmed, and spitting out the tough bits was awkward. The garlic prawns were tiny little shrimp that reminded me of what you might buy from the freezer section at Costco, but the sauce was fine, as was the tortilla. None of this was destination food, but service was friendly, we were allowed to linger over dinner, and the price came in at less than $20 pp with ample sangria for those who chose to partake.
I wouldn't choose this restaurant from a list of places in the area, nor from a list of tapas destinations, but can see going there under similar conditions. It was a pleasant evening.