My gen 1 Paperwhite expired of a cracked screen
a couple of weeks ago, so I have replaced it with the current generation 3 version with the higher resolution screen. The screen is noticeable sharper, but it's otherwise much the same.
As a result of this, I have discovered that...
Buying from Amazon results in getting a Kindle that's already registered to your Amazon account. I bought a book for delivery to it whilst it was still in transit, and the book downloaded as soon as I'd connected to my WiFi.
(SPQR, since you ask)
If you select a book from the "Cloud" section of the Kindle's home page (i.e. previous purchases), it downloads fine, but what you get isn't necessarily the same as what you had before. Some are in Kindle's new format (
see New Kindle Format topic), and some have had the title changed so Calibre doesn't recognise they are the same book as is already in its library. They can be matched up manually, but it's a bit of a pain if there are many of them that don't match.
Looking on "Manage your Content and Devices" on the Amazon home page, I see a number of other books that are showing as "Update available", which I can select to update the books I have on the Kindle (if the old Kindle which they are on was still working).