Storage
When it comes to storage the Amazon Kindle Fire HDX 7 has the advantage, arriving in 16GB, 32GB and 64GB guises. The Nexus 7 can only be picked up in 16GB and 32GB models, and if you want 4G connectivity you'll have to pick up the latter.
The Kindle Fire HDX meanwhile offers Wi-Fi only and 4G models with all three storage sizes, giving you a wider choice.
It's worth keeping in mind that the quoted storage sizes aren't the amount of available space you'll have at your disposable, as the Android operating system takes up around 4GB of that.
Also consider that neither tablet has a microSD slot to expand your storage options, so a 16GB slate is only worth it if you're going to be using it for emails and surfing the web.
Anyone thinking about downloading a heap of apps, movies and games may want to look to the 32GB and 64GB options to ensure they don't run out of space too quickly.
Battery life
As is the case with pretty much every tablet on the market these days the batteries inside the Amazon Kindle Fire HDX and Google Nexus 7 are sealed into the units.
This means you won't be able to buy a spare, charge it up and swap it with a flat one if the tablet runs out of juice.
The Nexus 7 houses a 3950mAh battery which Google claims is good for up to nine hours of multimedia usage, meanwhile Amazon reckons its power pack can last up to 11 hours - although it hasn't revealed the battery's capacity.
We found during our tests that both tablets gave pretty strong showings in the battery department, but the Nexus 7 was the better performer.
Each slate was subject to our battery test which sees a 90 minute HD video played at full screen brightness with various accounts syncing the background.
After the 90 minutes were up the Google Nexus 7 had dropped 24% of life, while the Kindle Fire HDX lost 32%.
This means you should be able to get a full days use without having to worry about running out of charge, although if you go on a heavy gaming or movie binge both tablets may struggle to make it to bedtime, especially the HDX 7.
The Kindle Fire HDX can extend its battery life beyond the 11 hour mark if you're predominantly using it to read books, as it has a special power saving mode when it's in reading mode.
