The pie charts below are from Tim Cook's presentation at #wwdc2013
. Aside from the inherent issues related to comparing iOS versions with Android versions (functionality offered, mission of the OS, etc.), I was surprised that Apple used pie charts to show the comparison.
From a #datavisualization
perspective, this would have been more effectively communicated using a 100% column chart with two columns.
I threw together a mock-up of what the chart should have looked like, while mimicking Apple's presentation theme. It's not as pretty as a final product would look like, but you can see that it is much easier to compare the relative shares across the two operating systems than one can do via pie charts.
's article for more on this Apples-to-robots comparison http://phandroid.com/2013/06/10/apple-vs-androi/