In general, I love Apple's products, but like Jon, I won't buy books from them, and for the same reason: I can't break the DRM. Every year, Amazon and other retailers receive hundreds of dollars from me for books I've purchased from them, but the only time I've ever bought a book from Apple is those rare occasions when they've been the only ones carrying a title I had a burning desire to read as soon as possible.
The prevalence of DRM isn't all bad, though. It has allowed indie publishers and authors who don't rely on it to make
significant inroads on the profits of the big publishers who can't seem to stay away from that customer-insulting crap.