The flickering issue is pretty much with every e-ink reader, unless you get used to it.
My dilemma: Should I buy iPad or Pocketbook?
If I buy iPad,
I can browse almost any type of file with hugely fast performance and sufficient battery life. But it causes me eyesores. And I am pretty much will be getting distracted for playing stupid addictive games. 
If I buy Pocketbook, I will get hugely stable battery life, non-distracting interface and I can concentrate on my book, and it's less expensive, too. On the other hand, I don't get speed flip-through (the slo-oooo-w page turn), not supporting all file formats and grayscale screen.
There is Pocketbook 912 review. Pretty recent.
912 isn't available worldwide. 902 is. The only difference is that 912 has touch screen. There is a also comparison video by same user.