One thing this article doesn't mention is the performance of iOS. It is often incredibly sluggish when opening or closing apps, moving between apps, unlocking the device and answering a phone call from the lock screen.

Personally, I'd rather have much stricter performance requirements for their mobile software than anything else right now. Having something that's almost an extension of myself lock up on me for a few seconds whenever I try to do something seems like pretty bad design to me.