The Kindle is a much more integrated experience, all done through the browser, so it's much less hassle.
No need for installing ADE
.
Since you live in the USA where Kindle book checkouts are available through OverDrive, I'd strongly recommend going with Kindle. In my experience, most books are available as Kindle books (although you may want to check first to see how many of your type of books are available as Kindle books
).