If you don't add an approval status to every document/]age, you should get an email reminder that you didn't finish reviewing the entire document. Also, it would be nice if you could see in the navigation if you are on document 1 of 4. Currently it shows the pages in each document.
We upload multiple pdfs each with multiple pages. It works really well for our approval except for the fact that it's easy to overlook a pdf or two.