According to the online reviews, Kindle is the best, but I am an open source type of guy, and I wanted not to be tied to Amazon. The Kobo eReader has reliability issues according to online reviews, and the Sony one seemed to be the ticket.
I first evaluated the eReader tablet by Sony, where one could check email, and it was slower than molasses in January. I needed WiFi and the Sony eReader with WiFi, Handwriting recognition, a web browser and such seemed to be the ticket.
It is performing as expected however it ain't no Apple when it comes to design. My particular pet peeve is the stylus. My better half loves using the stylus (doesn't get the screen all fingerprinty), however there is a huge design flaw. There is no damn place to store the stylus. The thingie on it that is like the clip of a pen, is too wide to make it stick to the accessory cover that I bought for it. There is no where to clip it to the body of the reader. To me it is sloppy design. The innards work fine.
This makes me appreciate all the more, the beauty in the design of Apple products. They would never let sloppy design like this go by.
Update: I wish that I had bought a Kindle.