I'm a tablet-oriented kind of person - I love being able to browse on a bigger screen than my phone, but a smaller screen than my laptop, and still be able to use all of the applications that I'd use on a PC to their full extent.
When my boyfriend bought me the Kindle Fire HDX to replace my broken Kindle Fire HD, I was so happy that I could continue using all my favourite apps, with some added features!
The tablet features a beautiful HDX display (apparently the 'X' just stands for more pixels) which brings up clear, crisp images - great for when I'm flicking through blogs and Instagram - however, this feature is standard in most tablets, so I wouldn't really consider it a major game changer.
It comes with at least 16GB of internal storage as standard. This is perfect for me, as I listen to a considerable amount of music, and I love trying out apps and reading on the go (although books don't tend to take up THAT much memory). You can also purchase the HDX in storage capacities of 32GB and 62GB, but the higher the storage, the higher the cost.
Amazon also offer a cloud storage service, which you get free with any Amazon tablet. This provides unlimited storage for Amazon content, i.e. products you've downloaded from Amazon such as books, music and apps. They'll also allow you to store 250 of your own imported songs for free, as well as 5GB worth of storage for your own files such as photos, videos and documents. I never reach this limit, as I tend to store everything in external hard drives anyway, but it's useful for those who don't.
It can be argued that no other app store really rivals Apple or Google Play. The Amazon app store is a little poor at the moment in terms of choice; major apps available through Amazon include Facebook, Twitter, iPayer, Candy Crush, Temple Run, Spotify (this was a deal-maker for me!), Skype and Pinterest, etc. Most other apps tend to have exclusivity with Apple or Google, including Instagram (which, if you're desperate, you can download on your Kindle Fire by allowing third-party apps and downloading through the internet).
Unfortunately, you do miss out on some apps because of the poor choice, but I'm pretty content with the apps that I CAN download.
The HDX comes with a supposedly HD front-facing camera - though the outcome of the photographs in actuality is rather poor, so if you are looking for a tablet with better photography capabilities, I'd go for the HDX 8.9, which has an 8MP rear-facing camera. However, it's really useful for video-calling friends or family (this is the only purpose I use it for).
In terms of usability, this is a consumer-friendly tablet with great features. It's light and easy to handle, and small enough to hold in one hand whilst reading. In terms of pricing, it's miles cheaper than an iPad or Samsung tablet, but it's really the app store you're paying for. If you can live without a giant universe of apps at your fingertips, I'd definitely recommend getting the Fire HDX 7!