Both devices received high scores when we reviewed them, 95 and 91, respectively. The two standout features on the Kindle Paperwhite are waterproofing and Bluetooth Audible support, so you can listen to audiobooks on the go. The Paperwhite comes in black or twilight blue, with 8GB or 32GB of storage. The latter will cost you $110, but that's still a $50 discount.
If you decided to save even more, going with the Kindle won't be too much of a sacrifice. The latest model includes a front-lit screen, touchscreen and support for Audible over Bluetooth. You'll give up waterproofing, get less storage (4GB) and be limited to black or white, but those may very well be tradeoffs you're willing to make. These discounts could make the readers especially appealing if your New Year's resolutions included reading goals.