Indeed - 6 *years* after the original post.
FWIW I've reverted to the Sony software that came with my reader. I've used Sony software previously and found it spectacularly bad: worse even than normal hardware-vendor-bad.
Sony Reader is pretty bad, but it's no worse than ADE and it does let you choose your file location. It somehow uses ADE for DRM without ever bringing Adobe's pile of poo into the foreground. I don't know whether it works for other makes of hardware.