My $0.02.
The 800 looks like it may be a good fit for me. I like the size: 8" without a lot of margins around the screen.
It looks like it has some nice functionality, like customization of margins.
But the main thing that nags me is there is only one button to turn pages. On my 505, I like (and use frequently) the buttons on both sides. If they implemneted full 90, 180, and 270 rotation, then I think the flip bar looks like a good choice, otherwise, WHAT WERE THEY THINKING?
The other minor annoyance is that there is no slot for the pen.