What Is the Pros and Cons of Jailbreaking a Kindle Paperwhite?

I would like to be able to put custom screensavers in my new Kindle Paperwhite, and have found this great how-to. Bot to do that, I need to root, or jailbreak my kindle, and I am not sure if I want to do that.

Can anybody tell me what the pros and cons are, of jailbreaking?

Also, a very cool thing would be to have the book that I am currently reading be the screensaver. Have anybody heard of such a hack?

Thanks in advance!