I think the only difference is, that you'll have ads on your kindle. I have the special offer and it doesn't bother me at all. You won't get ads while reading. The ads are on the screensaver and in the home menu.
Audio: Audio books sold by Amazon Kindle can be downloaded. Listening requires a Bluetooth-enabled headset or speakers. Own audio files cannot be listened to. Images: Only images that are included as illustrations in the books sold by Amazon Kindle can be displayed. Your own photos cannot be displayed. In addition, the screen can only display grey tones, not colours. Amazon Kindle is a closed system, which is probably part of the company's strategy. If you can live with these limitations, the Kindle Paperwhite is a fantastic device: I myself have about 400 books loaded, always with me when travelling, which is really great.