Re the Kindle Fire. I know nothing about the new one but a friend of mine who works in publishing was given one of the original versions and said it was terrible (I think unusable was the word he used).
Hopefully they've improved it, it seems the second incarnation of these budget tablets is...
Some of my son's friends have them. They seem good for the money but you have to remember you're not buying a Tab S or iPad Air 2 so they're going to seem shit in comparison.