I was excited to here that we would be able to restrict pages by individuals in 2.5 rather then the group limitation. My company wants the ability to be able to have pages, regardless of what space they live in that certain people are able to have access to.
I was a bit disappointed when I started to play with 2.5 and this new page restriction feature because a user has to be part of the Space as a group or individual access in order to view a page that has been restricted to their account.
From an Enterprise perspective I think it is important that if page access has been granted to a user for view and edit they are able to view that page regardless of what space it lives in.
The interface currently allows you to choose any user in the system. This was very deceiving because it implies that I can add any user to a page but that is only true if that user has access to the entire space.
Many organization are looking for ways to collaborate with people who are typically not part of their organization, are customers or vendors they work with. In confluence this becomes challenging because you need to create a space every time you need to introduce someone that is not consider privilege to viewing public information.