@delphin
Kindle cannot read ePub books, period. But Nook Touch cannot read mobi formats either, not outside of an Android app. like Kindle for Android.
The point is, Kindle users are not locked! The device uses mobi, Nook uses ePub, that's the main difference. There a tons of online bookstores where we can download mobi books without buying from Amazon. And if the book is DRM free, it can be converted via Calibre to mobi and we can also download and read ePub books via conversion. I don't see how a Kindle's user can be locked that way.
There is no such thing like the "best" ereader, but it's kind of silly keep pushing and putting ePub as the last goal for freedom. Without DRM, Kindle users can read whatever we want, even from others formats converting via Calibre, and would be the same for Nook. Running Kindle app won't allow the Nook Touch reading a mobi ebook natively, you will be reading because the Kindle app. Still you have to convert into ePub if you want to read it outside of Kindle app.
Don't root a Nook Touch in order to enjoy a Kindle ...
buy a Kindle reader and that's it.
If the other store is so good, why people install the Kindle app anyway? We don't need other sources, we're happy with Amazon's selection.