Considering that I just bought mine, maybe my opinion doesn't count as much. Here goes anyway
The size is nice and handy, although I think I'd like a 7-8 inch screen better. The text is very readable under bright light. The problem is, the lighting I am normally under is not overly bright. Under my typical room lighting, I find that the screen is not contrasty enough. The curious thing is, the contrast improves slightly if I am 30-45 degrees off from perpendicular. As for the button placement, although the number buttons on the side make more sense being next to the item on the screen, I think I would prefer them near the bottom, like the BeBook. It just is a matter of how I hold the reader.
I'm going to live with this thing for a little while and see if I can get used to the contrast issue and button placement. I have lots of time to return it if need be.
Edit: Oh BTW, I got the silver one. It was the only color Target had, but I think I would have gotten silver anyway, as it seems to blend better with the screen.