Disclaimer: I do not have the newest kindle fire, I have the one before it.
I decided to time my kindle fire today to see how long it would take to load WordPress. It took one minute to load it, then the browser closed itself. (All the browsers I’ve tried have done this. I’m starting to think it’s a kindle thing and not a browser thing.) So, that meant I had to reopen it and wait another minute. Two minutes to load a website. If I type something into the search bar on WordPress, you’re looking at at least a minute to load, plus the browser closing itself multiple times. It’s not just WordPress; it’s pretty much slow to load any website, but WordPress is the worst.
Bottom line: if you want something to read books on, get a kindle fire. If you want a tablet, do not get a kindle fire.