I've been reading e-books for over 15 years now. After over 2 years I still use my Kindle more than anything else. Before that my favorite reader was my Palm Tungsten W, although a Chinese Android tablet was really great even though battery life was short and after 2 months it died. I've used different computers including a OLPC XO as readers. The XO is a little big, but, worked well and I was able to manage my library on it. I use Calibre to manage my e-book library.
I'm considering picking up a Kindle Fire HD and seeing how that works since I enjoy my Kindle. Now that the Nook is including Google Play so a proper Adobe reader could be installed I may take another look at that. I hear the iPad works really well also. It looks like the e-Reader "wars" are winding down so that everyone has around the same functionality and quality.
Personally, now that the Nook can install apps that read text files and native PDF files I don't think a Nook is any worse a choice than the Kindle and it might even be better now that it is becoming an Android tablet. The Nook used to be a "retarded Android" tablet with too much of the good stuff disabled unless a user hacked it. Why buy a Nook and hack it when someone can buy an Android tablet for the same or cheaper?
Reading PDF files is still the biggest problem on e-readers. Just about everyone who writes a thesis uses PDF and pretty much every thesis or paper I have ever received has been published using PDF. Anyone working in cutting edge, or developing the cutting edge, needs to be able to read PDF files. There are so many PDF publishers that reading them can be difficult, especially when it comes to the way images are handled. How a reader handles the images in a PDF file is a big deal.
The iPad's popularity is partially because it is a great PDF reader and iReader works really well. iPad wins as far as I am concerned in every area except price and open source and that is a big deal. Since Open Source is huge to me Android is my choice regardless of other features.
Looking around and thinking about upgrading I like android tablets. Finding a quality 10" or so Android tablet seems to be a little on the difficult side. The Nexus 10 32GB is $500 bucks. Is it really worth the extra $300 over the Chinese 10" tablets? I'd need to invest in both of them to find out and I don't think I am going to do that.
These days I don't need to keep up with research and ongoing cutting edge development so my dependence on PDF files has been reduced. I think I am going to stick with the Kindle and cheap Android tablets for now.
By the time I am in a position to work on cutting edge development in Anthropology, if ever, the tablet and eReader wars should be completely over. The basic technology will be settled and pretty much everything will be the same except for a few features that appeal subjectively to different users.
Open Source is a huge deal. Back at the founding of the United States intellectual property laws were a big deal because we were entering the industrial age. Patent protection laws were restricted to 20 years to help encourage development. These days no one cares about encouraging development, everyone is just trying to make a buck so most intellectual property is protected by Copyright, not patents, because code is written like a book.
Copyright protects intellectual development for the life of the author plus 75 years. These kind of oppressive intellectual property laws suppress technological development.
Why is copyright so different than patent? Lawyers don't invent stuff, they write stuff and they don't give a rats ass about inventors or the common good. The blood sucking lawyers just want to make money. Copyright laws are literally retarding technological development.
Open Source is trying to change that, and it is working. All code should be open source. People whine about making money with Open Source, but, look at Google. Google developed Android and they are making money hand over fist. Google is also driving technological development.
In my opinion, as we enter the time of the end of the e-Reader wars, e-Readers need to be Open Source and they need to be able to handle the multiplicity of PDF files published by Masters and Doctoral candidates and Researchers.
If you are looking for an e-Reader Open Source development should be a primary concern in the selection of an e-Reader. Screen clarity is the second most important concern. After that, the ability to read PDF files and TXT files is important. Finally battery life is my final consideration. After that everything is gravy.