With the release of OS X 10.11.4 and iOS 9.3 a couple of days ago, iBooks now syncs your own PDF and ePub books (ones not from the iBooks Store) via iCloud. This is fantastic! I’ve been wishing for this capability for a long time.
The first time you open iBooks on your updated device, you’re asked if you want to use “iCloud for iBooks”. After that is turned on, any books added to iBooks are automatically uploaded to iCloud, making them available for download on your other devices.
To test it out I added a couple of PDF documents to iBooks on my Mac, and shortly after I had them available on my iPhone with the familiar iCloud icon overlay. With a couple of taps on the iCloud icons, I had the PDF documents on my phone. Love it.
Books was the last media type to still need old fashioned iTunes syncing, so with this update, I don’t need to use iTunes for syncing at all! The only reason I plug my phone into my Mac now is to create a local backup. I backup my phone to iCloud too, but having a local copy is a fail-safe.
Syncing books over iTunes never worked right either. It would often refuse to sync some books, and it was slow. In contrast, my experience with the new iCloud for iBooks has been flawless, so far.