I agree, nothing beats a real book. It is easier to keep track of pages and flip between them much quicker than a PDF. Don't get me wrong PDF's are real handy but not practical in all situations. I actually prefer to purchase from a local gaming store. The one near me needs a lot of support to stay open. The owner is still reluctant to place my ads for HARP demos/events because it isn't a game he actually sells in store. He wants people to play games at his store that he sells so he can make money to stay open. I remember when there was a gaming store in every mall, the good old days.
I did purchase both the PDF and soft covers of Martial Law and HARP Fantasy, I am awaiting College of Magics in POD version.
Oh and by the way, not everyone owns a PC or a tablet/laptop, so the printed books in store are great for people like that. One of my players only has a smart phone to view the PDF versions.