I took my family of five there and we had the loveliest, most authentic tapas I have had in the UK outside of London. Our waitresses were very friendly and explained everything to us. On the negative side, service was slow and somewhat disorganised.
At one point I asked for a couple of clean plates (tapas plates tend to get very messy); the waitress took the used ones away, brought out the pan fried gambas, and then forgot the new plates, which I had to remind her of, so of course the gambas was luke warm before I was able to eat it. There was a very long wait for desserts. When they arrived, our desserts initially went to the wrong table (fortunately there are only two tables so that was easy to fix) but that meant the other people had to wait even longer for theirs (they were supposed to be ahead of us). My daughter's coffee took about 20 minutes to arrive, by which time the rest of us had finished and were wanting to leave.
I also saw at least one couple being seated (at the bar) but then not being brought the menu so they just walked off. Two or three groups without a booking were turned away, even though it was clear that the reservation for the other half of our large table weren't going to show.
My advice to Ultra Comida: If the economics allow, you need to have three waitresses not two on a Saturday night (although two really good ones would have worked too). Also they really need to get a better system going for keeping a continuous flow of food to each group of covers.
A real shame because the tapas really was very good!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC