Apparently it does stuff I haven't done with it, watch movies or something.
Physically there is little different between the Nook and the Fire. What you're buying with the Fire is the whole of Amazon, you're tapping into a massive pipeline of content. Which you are definitely not doing with the Nook.
I did get a magazine for research and it's very close to unreadable. Sorry. The screen isn't big enough to both have the entire page on the screen AND be able to read it without a magnifying glass. This is probably iPad territory. You must embiggen it and read sections at a time. Very clumsy. I don't know how it's solved but it doesn't work for me.
I had a "major" problem sideloading What a Tomato in to the Fire. I wrote it in Word, converted it into filtered html, opened it in Calibre and converted it into a mobi. That didn't work. I called Amazon. The first person had no idea what format books are supposed to be in in order to read them on a Fire. She struggled to understand the explanation of what I was attempting to do so bumped the issue to the next level. They didn't understand it either. They wanted to dump this on KDP support. At which point I was mysteriously (thankfully) cut off. I started the process over again, converted from html etc. And that version worked.
This proves what I already knew--neither BN nor Amazon are completely prepared to deal with desktop publishing. Amazon is farther ahead but the lack of information they had regarding this basic procedure was pretty Amazin.
It surfs faster because of the Silk thing. Well all connectivity is bottlenecked at my DSL connection, correct? I connect at about 5 mbps which is fast. Shockingly fast for where I live. I don't see any difference between the Nook and the Fire in this regard. Maybe when it comes to watching video that's something else.
So the bottom line is that the physical devices are very similar and what you're getting is the company behind the device. And Amazon is obviously the far superior SHOPPING experience. If you got the reader to read...then there isn't much difference to be discussed. I'm used to the Nook, I like the look of it. I think the grey library in the Fire is somber and unpleasant. Wood is usually brown, that would have been better.
While I am very fond of the Nook and I like the audience at BN very much, Amazon wins. They figured this new world out way ahead of everyone else and being incredibly dynamic, they continue to evolve. BN is releasing the Touch with some kind of light element. Well isn't that nice. What about your inability to search the site easily? I have about 6 "reviews" on Dream Horse that someone use to write their own book about cats. I flagged these reviews weeks ago (they're 5 star so I'm not being hurt by their presence) but BN will never remove them. I don't know if there aren't enough tech people or support or whatever but they don't keep on top of any of the website issues.
So if I had to tell you which device to invest in, I'd tell you to buy a Fire. But I'm still going to use my Nook for all my pleasure reading.