Sorry for the delay in responding but, coincidentally several days after posting this I found myself in London. Why not continue the query and actually try a pizza at Franco Manca, I thought.
During our weeks stay, I asked several cab drivers and our hotel concierge about Brixton, the part of London where Franco Manca is located. All shared the same response, be careful!! Do not go at night, Some recommended not going there at all, which did nothing to increase in my wife's already minimal enthusiasm. There is a reason they are only open from 12-5 each day I found out. On a Saturday, I finally convinced her to go. All was well on the cab ride over, about 20+ english pounds or $30 plus dollars from central London. It was not easy to find as it is located inside a older building complex with many small markets, shops,etc. Its not a location you just stumble into, but rather a destination you must truly want to find.
Upon seeing Franco Manca we were quite surprised to see a rather substantial line in the middle of our walkway. Franco Manca's two small eating areas are straddled in between the main walkway of the shops. A line of 25 people waited for their turn to eat at one of the small tables. The outdoor temp was in the low 40 degree range at this time. All tables but two were outdoor with some heat, but not much. There are probably 10 tables total with a few seated as family style. Keep in mind this was at 2:00 in the afternoon on a Saturday. It took us 20 minutes or so to finally get seated and during our wait in line the very busy waiter took our order - a margherita and a pizza with organic pork and some chorizo. I chatted up the waiter a bit and even asked if Marco was there, since after reading all his posts I felt it would be great to actually meet him. Unfortunately, he was not there.
The pizza's were about 10-11". The Margherita had good oven spring and thick crust, the meat pie was a little flat with much less oven spring. I noticed as they put the dressed skin on the peel it was very wet. Charring was very common although a few looked to be excessive, but ours was just fine. I think the low dome can play into too much charring if the actual flames are too great. The cheese was excellent and both my wife and I enjoyed the flavorful sauce. The sauce had evidence of seeds in the sauce as they were not strained out. According to earlier posts by Marco I believe they use just sauce and salt. I would concur with this.
The crust was very flavorful and you could taste the ischia starter in the crust. It seemed to have a relatively high salt content. Overall very enjoyable experience. Prices at Franco Manca are very reasonable (cheap). Perhaps due to the area since the demographics do not dictate high price points. Interesting business model, find existing pizzeria that did not make it, replace with superior product, cheap price, get huge reputation and grow the business. Some people we spoke to in line did not come there for the reputation just good pizza and cheap prices, others had come because they had heard about it.
In chatting with the waiter, they use a temp controlled proofing area for the dough, 500 centigrade oven (over 900 degrees). Also, they use wooden proofing boxes, but the bottoms looked to be metal. I did not get a clear look at them. Their menu states proofing for 20 hours plus. The waiter indicated they will do between 300-350 pizzas on a Saturday. I would agree as in the space of time we were there I saw a tremendous volume go out the oven.
I see lots of growth for Franco Manca in the future. If they can make it in Brixton they can make it anywhere! Hey that sounds like a catchy tune??
One other thing. Catching a cab back is almost impossible. Either take the London Tube (subway), there is a station very close, or plan on arriving at lunch time to give yourself plenty of time to get out of there before dark. Its not the type of area you want to be in after 5:00.
Overall, excellent pizza, good job Marco.