I bought the print-on-demand version to go along with my 2013 premium reprint of OD&D. I know it's not really a supplement to the OD&D game in the same way that Greyhawk or Blackmoor are, but I think it belongs alongside them all the same. The overall quality of the book is very good. There was some concern on my part before ordering because I had heard that page 36 was the "wrong way around" on the PDF, and was afraid that it might be flipped upside down or something. This is NOT the case. The page, being a map, is simply presented in a landscape view on the PDF. It is printed as it should be, in portrait orientation, in the print-on-demand version. That being said, the quality of the some of the page scans (pages 7, 29, and 36) are subpar. You can clearly tell that they have been scanned in without any attempt to clean them up because they are off-white/gray in color, and the text and artwork is quite fuzzy. They are still quite readable, however, and I don't think it's that much of a deal breaker.
I noticed that WOTC has made supplement 4 "Gods, Demi-gods & Heroes" available for print-on-demand recently. So I wonder if they are interested in going back and making the entire OD&D catalogue print-on-demand. I will note however that the print-size of supplement 4 is incorrect. The product page lists it as 8.5"x11", when it should be 5.5"x8.5" (like the Swords & Spells print copy). Hopefully they correct this if they plan on bringing the other booklets over to print-on-demand. Also, fingers crossed for Chainmail!