I have an eBookWise too.
Here's the skinny for folks on the line:
Personal content - yeah, it's possible. Gutenberg is possible, RB is possible, etc, etc, and if you are enterprising enough, even .LIT files can be converted.
Complex HTML, offline reading - it's possible if you spend an hour or two getting familiar with sitescooper. Sitescooper, I'm finding, is the eBookWise user's best friend. I now, daily, read the Times, BBC News, the Guardian, and a handful of my favorite blogs on my EBW (yes, with hyperlinks).
Weight, readability - the screen isn't as green as it looks in the pics, unless you're reading it under direct sunlight. It *is* a green screen, but the backlight makes it appear black/white. It's not that heavy, either - if you figure out the correct way to hold it, it's nearly weightless.
My opinion: I love this thing. I wouldn't trade it for any Palm/PocketPC - I wouldn't even trade it for a lifetime of free martinis. The size of the screen is wonderful, and the price is right.
I demand alot of this machine and have used alot of the document converters. I'd be willing to answer any questions and help people out making this thing even more usable.