CreateSpace strongly advises its authors to order a proof copy before they publish. I strongly advise this as well.
Although I had been over my manuscript many times either on screen or with hard copy, reading it in real book form is a very different experience. I won’t try to describe it, because I can’t. Just take my word. The photo above is just the beginning of items I found that I wanted to change, tweak, say better, say differently, add, delete, checking for extra spaces, etc.
It is hard tedious work. But work that will make the book better as a result. I am painstakingly going through each page, noting changes with yellow stickies, and then after twenty or thirty pages, I make the edits in the document. I have about a hundred pages yet to go, so excuse me while I get back to editing the proof copy.