The device is missing some prominent hardware features that its competitors have, such as GPS. The Kindle Fire HD's processor is far from leading-edge: a 1.2Ghz dual-core OMAP 4460 Texas Instruments processor, compared to the more powerful quad-core Tegra 3 processor that powers the Nexus 7. After several hours of use, I found the tablet seemed to suffer occasional lags when opening apps and on occasion when using apps. Restarting the device solved the problem, but then the lags eventually reappeared.
The middling-level hardware isn't as surprising as you might expect, because the Kindle Fire HD hasn't really been designed to be an all-purpose tablet -- despite Amazon's claims to the contrary. Amazon CEO Jeff Bezos summed up the purpose of the Kindle Fire HD succinctly during the product announcement when he said, "The Kindle Fire is a service."
That service is the Amazon entertainment ecosystem. The Kindle Fire HD is a mechanism for buying and consuming Amazon entertainment content -- and it does a great job of it. The interface makes it simple to find, buy and consume the content, and new built-in features such as X-Ray for Movies (more on that in a bit) enhance the viewing or reading experience.
That's also why it doesn't have GPS or a back-facing camera -- but there is an HDMI mini-jack so you can extend the Amazon ecosystem onto your television. That's also why the Kindle Fire HD doesn't have the equivalent of Apple's Siri or the Google Now speech recognition/artificial intelligence technology.
Revising the interface
As with the original Kindle Fire, Amazon has buried the Android operating system deep under its own interface. However, if you liked the original Kindle Fire, you'll be pleased to know that the interface has been tweaked to good effect. The carousel-like main screen now functions much more smoothly than in the original Kindle Fire. The familiar "bookshelf" feature is now gone, replaced by a "favorites" drawer. All in all, the interface for accessing Amazon content is smooth, well done and simple to navigate.
However, the built-in apps remain an afterthought at best. For example, although the Kindle Fire has a camera, there's no app for taking photos (perhaps because the front-facing camera is mainly meant for face-to-face communication). The email client and contacts app both work fine, but don't expect any extras, such as the ability to turn email header displays on and off.