I would point out that anyone who shares the 'fear' of being tied to Amazon that you aren't really any more tied than using a Kobo or most other ereaders. Using calibre you can make ePub bookks work on the Kindle then you just sideload them like you do any book not bought from the devices prefered store so its only really the library lending you lose out on.
If you aren't wanting to have to sideload then You are also more likely to pay more to stay away from Amaazon as most of the time their books are at worst the same price but often cheaper so depending on how many books you will be buying the cheaper hardware prices may be misleading if you plan to stay in the devices Eco system
Nonetheless many of us don't want to be tied to Amazon and don't want to be sideloading. The library lending is really useful.
I still have the Sony PRS-350 I bought years and it is still going strong. At the time it was much better than the Kindles with the touch screen and smaller size, obviously now other devices have moved on.