I don't have a Kindle but I do have a similarly sized e-ink ebook reader. All of the technical documents that I've come across have been in PDF format which don't render too well on the ebook reader. They're great for a plain text document but if the PDF is formatted a certain way, with graphics, etc... you end up having to do a lot of panning and scrolling.
I like my kindle for reading books, but it usually doesn't do a good job with pictures, tables, diagrams, etc. For documents with anything more than text, I prefer to use my Android tablet.
I wa pleasantly surprised that my WingX subscription has a docuents library that incudes all he pertinent FAA publcations.
__________________
A&P, PP-SEL, Pathological Flier, EAA Technical Counselor
EAA Chapter 595 President,http://www.595.eaachapter.org/index.htm
Retired US Army Officer