I'm late to the party with this post from Mike, but it's a deep and important overview of how multi-user management works in "Locations" so wanted to be sure to share it here.

A Visual Guide to Using My Business Bulk Business Accounts For Multi User Management | Understanding Google Places & Local Search

Google is in the middle of a transition for bulk users from the Places Bulk dashboard to the My Business Bulk dashboard. Like the single location transition before this, it is frustrating and appears to a bulk user in the old dashboard to move excruciatingly slow*.

But the technical aspects of the transition are not easy, even for Google. This transition is made even harder by the vast difference in “ownership” rules between the old and the new dashboard and the many states that any given listing (let alone a group of bulk listings) might be in.
Head over to see the detailed screenshots and try to wrap your brain around the complexity of the various scenarios. It makes my head hurt just looking at it. Definitely am glad Mike covers bulk issues so well, because it's way more than my pea brain can handle!