[devilbunny]

Yes, the OS is locked. I misunderstood the point of your statement.

But all you are losing is the ability to use the Amazon store and borrowing that requires DRM. It still works fine as an e-Ink reader.

Anecdotally, the OSes on the really old ones are easily jailbroken. They have never updated them to an unbreakable one that I am aware of.

More than I can say for my first-gen iPads, which would still be wonderful devices for reading books today. I have a Kindle because it is, and long has been, the cheapest e-Ink device. It’s my reading-outdoors device; I don’t use it except at the beach/pool.