From what I can gather from searcing the web, there are, perhaps 3 or 4 comparable tablets on sale regarding price and technical ability. I think you look at what you will use your tablet to do the most proficiently for you and then prioritise your needs, such as speed, memory, screen clarity, apps, games, etc.
Obviously, each manufacturer will hard sell their own product and for the Amazon one, simply visit
http://www.amazon.co.uk/gp/product/ref=pe_98201_31982591_pe_hero/?ASIN=B0083PWAWU
Google the Kindle Fire HD 7" compare to similar tablets and then you should be able to decide.