We finally had a chance to try this pizza and it was worth the wait. After a Saturday morning at Eastern Market we got to Supino about 11:30 am to find a line out the door. Everyone in line said it would be worth it and they nailed it.
Got to place our order in about 10 minutes and pizza came out in another 20. Patrons convinced us to order the large for only 2 because they said that we would want leftovers. We ordered the Margherita and it was excellent - crust was thin and crispy and toppings fresh. We only had two pieces left but I didn't feel stuffed.
It was as good or better than the famed pizzas of Brooklyn.
Tips: order a slice to eat while you wait for your whole pizza. There are a couple of picnic tables on the sidewalk in front of the restaurant and down the block to eat your pizza outside.