[wallcraft]

The screens are identical, although some people report that the color of the device effects how they perceive screen brightness.

FBReader on the Hanlin does not use FBReader's library view, so you can't do the sorting by series. FBReader is only used as a reading engine, you could use it this way under Desktop Linux by using a file manager to navigate to the ebook file and then open that file using FBReader. The Hanlin does have folders, so you can arrange your ebooks however you like (but only in one arrangement). This could be genre/author/series/title for example. The Sonys have "collections" which are a kind of non-hierarchical virtual folder.

The metallic buttons on the right side of the Hanlin (labeled + and -) are for volume control under the standard firmware. Under OpenInkPot they are for font size. If you have SSH access to the Hanlin (e.g. from a Linux Desktop via USB) it should be easy to change these keys to paging keys by changing a configuration file. Note that the 9 and 0 keys are also paging keys and under OpenInkPot the 4 and 5 keys are section navigation keys.

EDIT: These two have the longest battery lives of any reading devices (both last several weeks), so you made the right choice based on this criteria. I never turn my Hanlin (EZ Reader) off, and almost never explicitly charge it because connecting to a laptop to copy files over is enough to keep it charged.