I can see where you're coming from with functionality. I agree that a keyboard is very functional in regards of user-search queries and possibly dictionary support. However, I think a sliding keyboard would be more practical, so you can put it away when you don't need it.
Also, I suppose my main issue with the 3 I mentioned are the glossy coverings. Readers are meant to be carried, handled, used outside, inside, etc.. The glossy white shell is very prone to visible scratches and fingerprint smudges, and any crack that may happen, you are not going to hide it. User Abuse is one item that should be on all manufacturers agendas.
But "shiny" sells. That's one thing that differentiates Mac from PC. Every Mac I have seen is white eggshell glossy and no amount of buffing and polishing can bring it back to out-of-box look. And this is for a Mac Mini that isn't really designed to be constantly handled, but simply moved around form one place to the next, perhaps 3-4 times a day max. For a reader that is held and constantly fiddled with every minute for a couple hours at a time average? It boggles my mind. Then again, this is only personal preference.
The 505 design, excellent. I like the row of buttons along the right side. The iPod-like circle and surrounding buttons, again nice. Never messed with one too intricately, so I'm not sure why they put a circle button on the left side. I would have mirrored the L/R buttons on the right, on the left, and possibly put another L/R button set in the center, right under the screen, so you could change pages with either hand, from either side or form the bottom, and put the 2 tiny circle buttons on either side of the 2 middle L/R. Then you could shorten the chassis, because that is a lot of extra space. Or more room to hold the device without hitting the buttons.
But there is hardly going to be one design that suits everyone needs. The Kindle and 505, Opus and iLiad, Jetbook and EZ Reader each has fans and detractors. It's never a win/win for everyone
