My fiancé has a Kindle Fire. It is really a book reader. The browsing is not very smooth and selecting options and buttons can be a real challenge. It is also not that great for downloading things other than books. I don't enjoy using it.
I have a Pantech Element from AT&T. For $10 a month I share my data plan and have 4g on the go and it automatically hooks to my Wifi at home to save data. It has the kindle ap and functions well as a reader, i have not tried it in the sun.
It has a external sd slot for extra memory. It has a nice browser and i can not think of anything I have not been able to do with it on the web. The screen is very nice and the games are of great quality and clarity. It has Bluetooth and has a good battery life.
The keyboard has a function called Swype. It allows you to slide from key to key to spell out your words for writing. It took some getting used to and is not as fast as typing but for most of my uses it works very well. It has almost completely replaced my laptop.
It also has a camera that does video and has a flash. Best of all it is built tough and is waterproof. I did have to sign a plan but it made the tablet cheap. I have really enjoyed it and it's nice to not need wifi when I travel.
The 4g streams like a dream. Sometimes I turn off the wifi because the 4g is faster.