Weak - it appears that Amazon does not want to invest in a competitor's e-reader devices. No search either. Very basic.

Can I use it to organize (and view) my PDFs ?

As a comment on how to cite Kindle books, the answer is pretty simple and I think it makes sense perfect sense; when citing Kindle books, use direct quotation:

"An example direct quotation might be this:

One of the author’s main points is that “people don’t rise from nothing”
(Gladwell, 2008, Chapter 1, Section 2, para. 5).

And that’s how you cite material from a Kindle or e-book reader. Have you tried this out yet?"

Source: http://blog.apastyle.org/apastyle/2009/09/how-do-i-cite-a-kindle.html

It shares with all Kindle readers a basic shortcoming for academic use: it doesn't show you the actual page numbers from the physical book. But other than that it seems ok - synchronizing annotations across devices is sweet.