Per recommendations, I went to Cigala last night. I arrived about 7:15pm, and the place was empty -- and no one else entered the entire time I was there.
That's usually a very bad sign, but in this case I think it can be construed merely as bad luck (for them, not for me -- although service was worse than usual, because they kept forgetting I was there).
I had the pan con tomate, the gambas a la brasa, and the curly kale. The pan con tomate wasn't the best I've ever had (needed more salt and garlic), but it was tasty enough. The prawns were cooked perfectly, and the accompanying romesco was good, although it wasn't a classic romesco. The curly kale was superb, and I could have happily eaten another bowlful (to the good of my iron values, no doubt). Everything was washed down with a glass of Santa Anita rosado, which was okay.
All told, it was a £16 meal, which was just fine with me. It was a perfectly good meal, but I imagine going with several other people is the way to see Cigala at its best.