So here is my first reading experience.
After several hundred pages of epub reading I can conclude the following things.
But let me first say, I come from four years of reading with the Sony PRS 505, so that is the device I can compare with.
Okay, first thing is, the HD e-ink white is by itself whiter than the 505 one, which makes the contrast much better and the reading even in the low natural light this days more comfortable. The page turning is much faster and so more responsive.
The light is nice, but in the end I prefer an external light source. So for me it is an addon which will be helpful when reading in an enviroment with really bad reading light like a train, an airplane or a hotel room.
The higher resolution makes the letters a bit thinner. Therefore I had to enlarge the font size for a better recognition of italic letters. Maybe I have to experiment with the built-in fonts.
What I missed was both page button to be configured to turn next, cause the page turning by gesture needed sometimes several thumb movements and is not my preferred method as I now know.
Also I had two or three times where the page turning did not happen until I turned again which resulted in two pages forward at once. But maybe there was some flaw in the epub.
The negative sideeffect of the touch screen are fingerprints.
Today I will try some PDF books and report back here tomorrow.