I've been using mine since last Friday and it's a phenomenal little piece of hardware. The interaction between the Mobipocket Reader on the PC and the device is outstanding and up until now I've been very satisfied with the Cybook.
But it's not all roses, I've also got some gripes, mainly the delete button not functioning (it's a pain to remove a demo or other kind of text) and the flat structure os the Library that makes it difficult to navigate. I remember that Microsoft Reader had a «Last read» structure making it easy to select a book previously read. No such thing on the Cybook. One has to navigate the entire Library just to get either to the RSS feeds or to the book one is currently reading.
P.S.: Hello DDHarriman, looks like we live in the same city. Small world indeed.
I've been putting up a kind of diary (in portuguese) on the BBdE forum (bbde.org), if you want to drop by and add some comments you're more than welcome.