I have just recieved mine, and the screen, and ebook support is excellent. However, the user interface is unintuitve and a little awkward. The menu's would have been made much more user friendly, if the numbered buttons were down the left hand side, matching the selections, instead of just clustered at the bottom. This has made me understand why sony made a touch screen reader, as the most natural thing is to try and select options by touching them, it's hard to stop yourself!
For my purposes, it's ideal as a reader, it supports and views a wide range of documents, and the screen is excellent. However, I wouldn't really recommend this to someone who want's to buy ebooks unless you know what you are doing, as there is very little help and guidance, you are pretty much left to your own devices to go off and get adobe digital editions and find sites that sell supported ebooks yourself.
On to the rest, as you'd expect from eink, the screen is excellent, comfortable to read and sharp. whenever a page turns, the whole screen inverts first, and when small sections are updated they do the same, presumably this is to even it out and prevent burn in, but it is a little odd at first.
Because of the screen, like all eink, takes a second to update, it feels a little sluggish, but that will be the same on all readers using this technology. The reader is recognised as a removable drive, and the sd card as a seperate drive, so adding books, and organising them into folders is reasonably straightforward, although i'd recommend something like caliber to manage your book collection and handle the transfers/format conversions if you have a few, especially in a few different formats. You have to swap between the sd card and main memory, the library won't mix the content of teh two, so you will probably find youself putting a large memory card in it and sticking with that.
It's faily solidly built, and rather nicely, comes with a book like leather case, unfortunately though, it doesn't support sdhc cards, so 4GB extra is currently yoru limit. The buttons are functional, but not great, and it might just be me, but i'd have liked the page turning buttons on both sides, the 9 & 0 buttons do the same job from the right hand side, but are not as comfortably placed.
So in summary, a very nice, very functional, ebook reader, which supports a wide variety of formats. That is just let down a little by it's clunky user interface, and lack of real user support for getting content.