Limits of app access tokens [closed]

Question

Like many other people on the web I was worrying about the expiration of the 60-day access tokens because my app will do some async publishing and I cannot initiate re-athorization because those jobs run on the backend without any user-involvement. Then I disovered that there are "App access Tokens" (http://developers.facebook.com/docs/concepts/login/access-tokens-and-types/). And they can be used to publish 'on behalf of the user' without expiring. My question is: What are the limits of these app-tokens when publishing? Is there anything I can't publish with them?