Still love my 650. I have a spare one, plus my wife has one (in use spare

). Also a couple of 350s.
Still like the ability to arrange the books on the Sony.
But it is harder to get books. B&N no longer allows you to DL books for sideloading. Kobo is selling books in formats that do not work on the PRS series.
Books-A-Million is one source. Or Amazon and converting the Mobi to EPub.