I'd love to be able to use the controller to browse the web, etc; usually I have my hand resting on my mouse on my desk, but i've been developing tendon issues and having my hands in my lap would reduce the strain in my fingers when I'm passively reading or researching.
I've tried adjusting the settings in Steam for "desktop layout", but moving the sticks and pressing buttons in chrome doesn't seem to do anything.
Last I checked, Kobo will be better specs (screen, water proofness and connectivity) for the money, and if you're technical it can be modified very heavily, including pretty easily user expandable storage.
Kindle will have a more seamless Amazon experience and maybe better support.
I have a Kobo Clara HD, and I love it to bits. Warm temperature backlight, and I have installed custom firmware on it which lets me use a different reader app, and run an SSH server on it so I can remotely transfer files etc.