Thank you all for the comments.
Anthem:
You mentioned Kobo is not the best device for pdf. Is Onyx better than Kobo?
As regarding translations its good tool. But again single word dictionary would also be helpful. Though I have to agree I did find tolino visions dictionary good.
Somewhere it is already mentioned sony has by far one of the best offline dictionaries, but adding free dictionaries for missing laguages to it is next to impossible. Or did I get this wrong?
Also they also have fairly good pdf support.
mgmueller,
I notice you are in Augsburg. Not far from Munich

.
Do you know any place where I can try Onyx?
You seem to have tested/used quite a nice collection of ereaders.
Any suggestion would be helpful.
Thanks & Regards,
-dkg