Keep in mind that this is my first device so I have no comparaison point.
So far so good, Calibre works great with it and I have added a lot of books easily.
As for the sorting system, it allows you to sort it through titles, authors and folders. The metadata read is ok with epub but doen't seems to work with PDF....
You also can manage your files, directories and file names directly in the device.
A lot of fonts (custom), resizing, margin etc options but I guess this is a classic among readers.
The page turn rate is fast enough for me, i would say a bit less than a sec.
The built in dictonaries are a must for me, definitions are good aswell as translations. There is actually a lot of them.
Sometimes some kind of "shadow" from the previous page occurs but I believe it's usual and not only with this device (?)
For PDF reading the zoom is easy to use with 2 fingers (2 fingers > you enter "zoom mode" the page become grey > tap on the screen to exit mode) and it keeps in memory the zoom level you choose for the rest of the pdf.
The "auto-scale" option seems to work very good aswell.
I like the screen definition but having no point of comparaison I really can't juge....
I didn't try the rest of the device but if you have any questions and or any test you want me to do, feel free to ask !