@Kenneth_irl: My 4GB PW2 originally came with 5.4.3.2, so it basically just comes down to how long ago the device was built, the variant is irrelevant for new devices, since Amazon now only ship 4GB ones anyway. Of course, that also means that this ensures unsealed 2GB ones are shipped on something usable, but since the S/N is not visible on the box...
.
@Waylander: The PW1 is terrible, don't. The Aura is... a Kobo. I'd strongly suggest you try one before you jump ship, they have their specific quirks, some of which might be a deal-breaker, especially if you've used a recent Kindle before.