For years I've read using my Android phone with FB Reader. It served me well, but battery life was poor, the screen was keeping me from sleeping and Library access was poor - too many books, not enough methods to search and keep track of what has been read and what has not.
I purchased a Kindle to deal with these issues.
What I got was a device that is very slow, has a screen that might have a higher resolution than my phone, but the black text isn't actually black, the back-light isn't very bright, there is no auto light level and the overall reading experience leaves me disconnected from the content.
The power button on the bottom is precisely where my pinky (little finger) rests to keep the Kindle in my hands, so I've lost count of the number of times I've accidentally powered it off while readjusting the device in my hands. There is no ability to rotate the screen 180 degrees, only from Portrait to Landscape, which helps a little with avoiding the power button.
The device is not comfortable to use in bed, too big to lie on your side to read, too heavy to hold above your head if you're lying on your back. Sitting position only.
The library management is in my experience atrocious. Not only is it hard to find books, all you have is a single search box, no categories, series or topics, there is no way that I've found to manage a library with 960 books in it.
Battery life seems random. Perhaps it's doing something in the early days of uploading a library, but if I leave it for a couple of days, it seems to lose 20% of battery whilst in "deep sleep".
From the supplier I purchased this Kindle, I've got 30 days to trial it and at the rate it's going I'll be taking it back.