OK, there is a - I wouldn't call it a problem, but it definitely gave me a start: originally, when I opened the Library, all the books were listed together. As I have thousands of fics which range from 100-word drabbles to 50,000 word multichaptered fics, plus some fiction and textbooks I transferred to the SD card, plus those free books that came with the device, I thought this would make the Library useless to me.
That is, until I remembered to check the menu and see if folders were enabled. So I would recommend you check the settings before flailing about like I did.
It does feel like it's faster after the update. I'll see if that's true regardless of the number of files on the card.
Also, for those who don't like leaving fingerprints all over the screen, I just discovered that
Derwent rubber shaper used in charcoal and pencil drawing can be used as a stylus.