Here's our breakdown of how the Amazon Kindle 7" HDX stacks up against the Amazon Kindle 7" HD. 

Pros and Cons of the Amazon Kindle 7" HDX: 

First off, the Amazon Kindle 7" HDX has a higher resolution display with better pixel density. It also has a powerful quad-core processor. Double the amount of RAM, an extra 64GB model, and a later Android version also give it additional advantages. Furthermore, it's lighter compared to the Kindle 7-inch HD.

The Amazon Kindle 7" HDX doesn't really have any con that may put it behind its predecessor, save for perhaps the price. The only real questions is: just how much better is it?

Pros and Cons of the Amazon Kindle 7" HD:

The Amazon Kindle 7" HD doesn't seem to have any features that could give it an edge over the Kindle HDX. It matches the Kindle HDX with the same camera, but lags behind in all other features. It has half the RAM as the HDX and weighs almost 95g more. Even the same-sized display is not as vivid. The 7" HD doesn't have any GSM feature, which puts it far behind its successor.

Specs:

The Amazon Kindle 7" HDX has a 7-inch IPS LCD display with 1200x1920-pixel resolution at 323ppi. It weighs 303/311g and measures 9mm in thickness. It runs on customized Android Jelly Bean and a 2.2-GHz quad-core Krait 400 CPU. Other features include 2GB RAM, 1.3-MP single camera and storage configuration of 16GB, 32GB, and 64GB.

The Amazon Kindle 7" HD has a 7-inch IPS LCD display with 800x1280-pixel resolution at 216ppi. It is powered by custom Android 4.0 and runs on a 1.2-GHz dual-core Cortex A9 processor. It weighs 395g and measures 10.3mm in thickness. Other features include 1GB RAM, a 1.3-MP camera, and availability in 16GB and 32GB storage capacities.

Talking Points:

The Amazon Kindle 7" HDX was announced in September 2013 and released in October the same year. Amazon later released a new 8.9-inch larger Wi-Fi model in November. The latest upgrade was released in September 2014 with an even faster CPU and GPU. 

The Kindle Fire HD was unveiled as either a 7-inch or a 8.9-inch tablet in September 2012. The Fire 7" HD was released in September 2013 with a more powerful CPU and customized Android OS.

Prices:

The Kindle Fire 7" HDX 16GB model starts at a price of $179 on Amazon. The Fire 7" HD starts at a price of $114 on Amazon.

Conclusion:

The Amazon Kindle Fire 7" HDX is clearly the better device among the two. It has two times the RAM and almost two times as powerful a CPU as in the 7" HD. Besides, it has a 64GB model, which is absent in the HD. Thus, the Kindle Fire 7" HDX is the easier choice among the two tablets.