Oscar and I went to try them out on Friday. 6 euros gets you this giant heaping plate of ears with the sauce and bread. They think you're weird if you don't order anything to drink, so I got my usual copa de tinto and Oscar went for a vermút (vermouth).
The bartender took a handful of raw pig ears from a giant plate next to him, plopped them on the stove, sprinkled olive oil on top of the mess, and chopped/mixed them with his knives for a while until they were ready, so you knew they were cooked as fresh as possible. The ears were mostly cartilage and fat with some meat sticking in places. It was a peculiar taste. As mom would put it, "it's an acquired taste." Definitely worth trying if you're in Madrid! This plate can easily be shared among 3 or 4 people, because that's a lot of pig ears!