When I started I bought an EZReader as it handled Adobe DRM (and had a decent price point) which was what my local library offered.
When that wore beyond my ability to repair, I got an e-ink Kindle WITH BUTTONS. I really detest brand specific proprietary formats (w/wo DRM) as a nasty way to lock you in. I like to return buy because the product is BETTER, not because I am shackled to that brand.
Looking forward
Back light (LCD) and touch are (I even use a mouse with my Touchpad equipped laptop whenever possible) my downfall. When the K4nt dies, I don't know. Paying an additional $200 just to get buttons
on a E-Ink device.
If I am lucky, it will outlast me.
