[soulfuldog]

The only advantages I can think of is that you can automatically have your booked stored in the Amazon cloud when you buy from there, and you can easily sync if needed. Plus, you can take advantage of getting the books delivered wirelessly to your Kindle. I tend to download all my books to my computer so I have a copy stored in Calibre, then sideload them onto my ereader, but even I occasionally buy a book from Amazon and send it directly to my Kindle to read - it's just so quick and easy to do so.

That apart, buy from wherever, it's not like kepubs v epubs, so if you are happy to strip and convert, despite all the "locked into Amazon" stuff you read, apart from the 'ease of use' of buying from Amazon, you can buy from wherever is cheapest. That's exactly what I do, the difference for me is, that is usually always Amazon.