I recently signed up for Deep Book data (ARCA, NSDQ, and NYSE). I have to say, it was cool at first, but I don't think I will be keeping the Deep Book data next month. At first I felt like it gave me an edge, but after having it a week, I'm not so sure.
I just thought about it and so many orders are hidden, so I'm not getting the whole picture. I feel like I can trade just fine using the top of the book. If there was no way to hide orders, I would definitely keep the Deep Book data.