I think the first one I received was a copy of Paradigms of Artificial Intelligence Programming, probably around 15 years ago. I complained about it back then. These days, all books published by O'Reilly are PoD. Quality ranges from bad to worse. It's such a shame. They used to use RepKover binding like NoStarch does.

I've found low volume books from Lulu.com to be perfectly acceptable, though. Although the hard cover does feel a bit cheap.