The Kindle e-reader was the original ‘Amazon device,’ and the heart of its e-reading lineup has long been the Paperwhite. So much so that Panos Panay, Amazon’s head of devices, described it as the “most loved Kindle” and the one that, as he admitted, owners with the current or previous-gen models are hesitant to upgrade.That reluctance notwithstanding, Amazon has set out to make the best Paperwhite yet, with the all-new Kindle Paperwhite and more premium Kindle Paperwhite Signature. There