I live just down the road from 66 Books. It's a bit of a shame for the locals now it's become so insanely popular. You could always just walk straight in at any time before. Saying that, if you follow them on Facebook they do update about the waiting times. Being so close I can just pop down when they say there's no queue! I always pick up as I go too. I'd say take layers, some water and maybe something sweet to keep you going! Some of the stock has been there for years, particularly the classics. I see them everytime I go. The more recent/modern books seem to go quicker.

Do they have hardcovers as well? Or is it all paperbacks?