I sometimes wonder if people have too high an expectation of an e-reader.
My kobo mini is 'slow' on page turns compared to an iPad or tablet, has
lowish contrast ratio (complaints from somebody who reads on an iPad
all the time), but imo is no worse than my sister's K2.
Compared to some cheap paperbacks I have read or a daily newspaper
it is perfectly acceptable.
i got it to read books and so long as it is legible I can live with a less than 1
second page turn (comparable to physical media) and a contrast ratio better
than most paperbacks or newspapers.
If I wanted high performance, pretty pictures and brightness, I would have
paid a lot more and bought a tablet.