I've got an Adobe DE book I downloaded from my library on my 505 right now. It works okay, but not perfect. In the small size it's way to small to read comfortably. When upping the size, the reflow helps, but since it just reflows the page and not the whole document, there are abrupt breaks every other page or so.
But I can't complain--lots of free books available for my reader now.
dordale