Now in the Google AdWords Report Editor you can do cross-account reporting to see all your important metrics across your manager account in one single report. Google quietly announced this new feature on both Google+ and Twitter.
Here is a GIF of how to build the cross account report in this tool:
Quickly create cross-account reports to view your most important business metrics at scale with the Report Editor—now available in your manager account in the new AdWords experience.
Here is the help document on this report editor.
How do you plan on using this unlocked feature?
Forum discussion at Google+ and Twitter.