If you want to read in the sun, Kindle. Otherwise, for everything else you’d like to do, then the iPad. There’s a reason iPads sell so well. Not many people say, “Oh, no, an iPad, I wanted a Kindle…”
I saw walmart has a thanksgiving special for the ipad mini. $300 and you get a $100 walmart card, pretty good deal if you ask me for $200 bucks. I would go with the ipad.
Think about what you are going to use it for then make sure that is supported by the platform.
My experience; Bought an iPad mini last year and would make the same purchase again. The screen is nice and clear, lots of apps available no matter what your interest and the size and weight make it it easy to hold. To be far I have not used a Kindle but did look at them while making the decision and the FW convinced me to get the mini. As usual she was right.