Build quality is excellent but since it doesn't have rounded edges, it's not comfortable to hold in one hand as Google's identically priced Nexus 7, and it's considerably wider when held upright.
It weighs just over 300g and in practice it's impossible to tell the difference in weight between the two.
There are just two ports: a headphone socket and microUSB. Unlike the Fire HD, the HDX has a front-facing webcam which can be used for Skype calls.
Set into a glossy strip on the back are stereo speakers which are surprisingly good for watching videos or catch-up TV from iPlayer, and even listening to music.
Screen and hardware
The HDX has a higher resolution screen than the HD and Amazon says is has 'perfect' colour accuracy.
There's no denying that this is a fantastic screen. Photos look great, with vibrant - but realistic - colour. It's very bright, too and has great viewing angles.
However, there's a problem. Getting perfect colour accuracy without compromising on battery life, Amazon has used blue, rather than white, LEDs. For the most part, you won't notice but any screen with a white or light-coloured background at the edges has prominent blue strips.
If you're thinking of buying the Fire HDX primarily as an eReader, this might put you off. The blue strips are just as noticeable whether you dim the screen or run it at full brightness.
In terms of storage you have a choice of 16-, 32- and 64GB models. You can't add storage via a microSD card, so choose wisely.
There's also the option of a 4G model in all three capacities but you'll have to add £10 to the cost of any model if you don't want to see adverts on the lock screen from time to time.
Bluetooth is standard on all models, but only 4G versions have a built-in GPS for accurate location services.
Amazon now includes a mains charger in the box, something that was missing from previous-generation Kindle Fires.
With a quad-core Snapdragon 800 processor – the same as you get in flagship smartphones - the Kindle Fire HDX is an outstanding performer. It's faster than the Nexus 7 in all our benchmarks.
In general use the Fire HDX feels supremely fast.
Amazon says you can expect 11 hours of mixed use from the non-removable battery, or 17 hours when reading books. If you play videos non-stop at full brightness, the battery will last less than seven hours.
It might not look like Android, but the updated Fire OS software is based on Jelly Bean. We like it a lot: it's easy to use and fixes many niggles that annoyed us in previous kindle fires.
Pretty much everything can be stored in the cloud, which is why there are uttons at the top of each section marked 'Cloud' and 'On device'. By default you see the Cloud view, and tapping on an item downloads it immediately, and there's hardly a delay before you can listen to a music track, read a book or use an app.
Good as the interface is, the Fire HDX still locks you into Amazon's world. It's no hardship being limited to buying ebooks and audio books from the well-stocked libraries, but the choice of apps in Amazon's Appstore lags behind Android devices that have access to the Google Play store.
BBC iPlayer is still the only UK-specific catch-up TV app, and you can't watch shows via the web browser because there's no Flash support.
You won't find Google apps, either, such as Maps, YouTube and Gmail. If you know what you're doing, you can install these and other Android apps using a process known as side-loading.
With the choice of LoveFilm Instant or Netflix, we've no gripes about streaming TV shows and movies.
A feature that's exclusive to HDX tablets is the new Mayday button. If you need help simply swipe down and tap Mayday. You can speak to one of Amazon's Tech Advisors any time day or night, and they can either guide you through the features or remotely control the tablet and fix problems for you.
The Fire HDX is a great tablet with excellent performance and a great screen, but one that suffers from a couple of problematic flaws. The blue light leakage will annoy some people who like to read a lot, while the lack of apps will trip up anyone expecting the choice you get on an iPad or Nexus 7.It's a great choice for undemanding users who will benefit from the closed,
safe, easy-to-use ecosystem and the free tech support via the Mayday button.