I bought a nook last fall. Don't have any experience with a Kindle. It does display PDF and other formats. Go to Barnes and Noble site and look under the nook features and specs and they will tell you what it does.
I like it as a reader, don't have to carry a bunch of books when I travel. Don't expect it to do well surfing the web. Very slow and cumbersome.
If I had to do it over again I would have saved for an Ipad I think