Well, my HDX is going back to Amazon. When reading books, and especially in the web browser white backgrounds get a dark blue "haze" on the outside edges of the screen. If text goes to the edge of the screen it's very disruptive to reading.
So I'm returning it because it's defective, but not replacing because of additional problems I just can't overcome.
1) Amazon store is lacking apps. I'm a huge fantasy football junkie and there's no ESPN fantasy football app.
2) The "OS" is frustrating to use. It's just one ADHD explosion of icons. You can't create folders to organize. Amazon tries to force you into "online" content and you have to really dig in to get to the "offline" stuff.
3) Kindle Freetime for kids just has too many issues. The HDX allows you to offline cache prime content. But that stuff isn't available to Kindle Freetime. If I download my own movies to the device you can't add them either (that I can tell). Plus with the iPad we have, you can affix cover art to video files and it shows on the iPad. With the Kindle it's just a preview of whatever the first frame is. Plus it doesn't show the file name.
With the books you download they are basically scans of a book and the text is so small you can barely read it. No way I could give most of the "books" on there to my learning to read 6 year old and expect her to try and see the text.
Overall I'm just really disappointed with the device and had very high hopes for it to be a great household tablet for travel and the kids. It's fast, very nice size/weight, and the screen looks great for movies. It's just a letdown when it comes to basic navigation and use.