Cat R.
Google
The sandwich was very good, but I don't know that it's worth a long queue to take away. A better option, if you can swing it, is to get a seat at the bar. I went by myself and had no trouble finding a single seat. By the time I left, there seemed to be a short wait.
Once at the bar, you're treated to a show: Philippe (I think that's his name) seems to run everything behind the counter, and he kindly and quickly delivered my sandwich and wine. When I asked for a glass of water, he was quick to oblige with a smile.
The other benefit of being at the bar is you can talk with anyone who seems social nearby. The lovely gentleman to my right lifted his fresh beer to my wine with an, "à votre santé!" as we both admired the chocolate filled choux pastries placed right near us, waiting to be delivered to a nearby table.
I've heard you can only order the sandwiches at the bar. Be prepared to bring cash as they don't take CB for anything under €13. After watching the people working so hard in front of you while you eat, you might just want to round up your cash payment by a few extra euros as a tip.
Being relatively shy, I was intimidated by the hustle and bustle of the interior as I passed by at first, but then I turned around and forced myself to go in to see what the hype was all about, and I'm so glad I did. It made for an unforgettable afternoon.