My take on this: I got the Kindle 2 a couple of years ago and it still works great. I got the basic Kindle ($69) about a year ago and use it all the time for reading books. I have taken it backpacking several times and it is light and holds a charge for a reasonable time. Works great for reading books and will hold about 1400 and an infinite number in the cloud. I took it when I went walking in Scotland and stayed in B&B's. I was able to read email every night and read the home town paper (poorly formatted but readable but that is the local paper not the Kindle). I could reply to email but the keyboard stinks so replies were brief but assuring to the folks back home. I recently bought a Kindle Fire which my wife "borrowed" so I had to buy another one. Great for games and graphic stuff but heavy and only holds a charge for about 8 hours.

If you just want to read while hiking and have limited web access the basic is great. If you want to play games while sitting in your chair the Fire is great. None of them wash your socks but then what are you getting one for.

Amazon just came out with a Paperwhite which has a lighted screen and a long battery life. I have no experience with it but my son in law bought one for my daughter so I will get a chance to play with one.

I have no experience with any of the other units but I am happy with mine. It is like most of my backpacking equipment. It works for me so why do I want to change for marginal improvements?