Only had this a couple of days, and really only played with it for a few hours, but I'm a bit meh about it to be honest.
As a device, it's smart, the screen is crisp, it's light, has a rubberised back so easy to grip. It's touch screen is a little vague, having been used to iPhones, the UI comparison is not up to that of Apple products. Scrolling is clunky and what gestures it uses are somewhat cumbersome compared to my MacBook or iPhone.
The software is quick, hasn't yet shown any glitches. Takes a bit of use to work out how stuff works. What I bought it for was to hopefully get some car magazines on it as well as some technical manuals. As yet I've only downloaded a few books and for a laugh a copy of viz. seeing as being an e-reader is really the main role of the device, it is very frustrating trying to read on. Books which are formatted are fine, but as a trial run with Viz, the page formatting mean in Portrait you get a page view that is far too small to read, and the flipping to landscape you get a double page view which is miles to small to read. This maybe me being unfamiliar with the settings though.
A very big plus has been its PDF viewer and its file system. This weekend working on Dave's new car, I needed a few circuit diagrams, a quick trawl using Silk, it's own web browser and I'd found two or three PDFs, each downloadable. Now rather than carrying a laptop to the car, using the Fire, it was easier to use in situ than a laptop. Also with it downloading the file, I then managed to email it on to Dave using its email function.
All in all, it's a nifty little device, for the price I'd say it was a fair buy. I don't feel it's aim was solely as an e-reader, which is fine, but Ada tablet I believe it falls short of the mark a bit, which is reflected in the price.
Still early days mind!
(Posted from my iPhone)