We read all the TA reviews and had to try it. Guess what, they are right! It's not too difficult to find, just head to the left of the curved pallisade in Pizza Plebicito, up the flight of steps on the left, then at the top go straight ahead and it's about 80 metres up the narrow street on the right.
Place was nearly full, it has about 30 covers squeezed into a smallish room with an open kitchen and the pizza oven behind. We ordered frittatinas and arancini to start, one each (too much), followed by two of the most expensive pizzas and a glass of house red (3€) each. Pizzas range from 3 - 6€, drinks are cheap (66cl Peroni 2.50€) and service is friendly. You'll be cheek by jowl with your neighbour, so hope they're sociable. We had two e. european Star Wars nerds next to us but it didn't detract too much. Total bill 27€ with an extra glass of wine, and no pressure to relinquish seat despite queue spilling out the door by 2.00pm. This place is a gem.