IMO, there is a significant difference between how information is presented on web and how it is put on the dead-tree—a one-to-one reconciliation of style and presentation isn’t possible. Although I could be wrong about this!
CSS paged media extensions create the print-based context of pages, kinds of pages for you to work with and PDF specific stuff like bookmarks. Using tools like PrinceXML or Antenna House you then generate the corresponding PDF.
I wouldn’t want a one-to-one reconciliation because, to me, PDF is more for reading offline in paper than it is reading online in a screen. That said there are a lot of things that you can do on the web that you can also do in a PDF document.
Is there a study on how many people choose to read content offline by printing to PDF or on physical paper vs. on url itself? I mean we know that the number of people who read a blog online far exceeds the number of people who end up downloading/printing it before reading.
People can’t easily print content so why would they try? Not even the browsers default stylesheets account for printing. Also, note that books and long-form text are a completely different monster
I used to print sections from Safari (when I was subscribed) to have next to me when working in code so I wouldn’t have to switch tabs or browsers when looking for a specific thing.
As to your specific question, no… I don’t know if there are studies about people printing blogs for offline reading. As far as books are concerned, the only element I found was about O’Reilly going for PDF rather than epub or MOBI