Also being able to configure the layout is good as it lets you limit the damage your users can do when they start to use page level formatting. As well as speeding up the load time by leaving out some of the functions that aren't necessary for most users.
A must have for extension.
For example, I would like to have seen the stylesheet editable through the configuration screens, and the ability to group custom fields relating to individual categories so these could be viewed as a group.
But these are minor niggles that can be lived with, because otherwise AdsManager is a top component.