[GraemeJ]

It lets me create new PDFs, modify annotations in existing PDFs (for converting MS annotations to PDF annotations), query for things like PDF bookmarks, table of contents, and I believe it also uses much less memory. Creating PDFs was critical for printing support, exporting files and exporting annotations.

OK, I can see why you went that route.   

I'm still a little concerned over reports of poor quality though.  I have quite a few scans that are none too good to start with.  These are mainly various Fakebook scans, many from years ago (and scattered all over the net) which I would think many other users also have. Much more degradation, of some of them, would make them unreadable!

I guess I'll just have to see how it goes.