The channel features are a nice! The only bad thing is that the data for the channels are not real time. In the FAQ it stated that results for the channel could be 2-3 days before they are updated.
Data that wasn't lagged 2-3 days would be useful when deciding where to put ads. Testing if ads do well on specific pages, or locations within a page for example...
But definitely happy it has it now... even if it is lagged.