I have a prs 650 recently acquired. I am astonished at how difficult it is to do a simple task of grouping books into collections. What I can do in PC file manager in a few minutes takes so much fiddling on REader. It chooses Collections by Tag info, so you have to edit the metadata laboriously. Also there is no table of contents access on the Reader for easy book navigation.
What total crap
Very disappointed in Sony, for its control freak approach to customers. Sony must think we are really stupid and going to put up with this dumb functionality