It also has 2 GB of internal Flash memory and you can further enhance it up to 32 GB via the micro USB port. (goodereader.com)
They're all broadly similar: they're all light, portable, and handheld and they all have large internal flash memories that hold hundreds or thousands of books. (explainthatstuff.com)
If one is using cloud and / or external HD backups, the small internal flash memory should not be an issue. (bgr.com)