Probably a reason why the authority requires a lengthy testing period in which we use two different EFB systems side by side, the old windows xp based one which served us well for nearly 15 years and the new iPad based one. If one goes belly up the other one is still available. Haven't had paper charts on board for more than 10 years now.
The iPad seems to face issues with pilots involuntary upgrading every time a new version of either the iOS or an application becoming available, even if it is not cleared by the company yet. For example we cannot upgrade to iOS 8.3 yet as the airbus apps won't work with it.