Talking to casual users, "my iphone/ipad is slow" was a reason they were motivated to purchase the newest model of iphone. When it comes to repeat purchases, I wouldn't find it difficult to imagine that responsible for double digit percentages of new iOS device sales.
Unfortunately for Apple, Steve Jobs is dead and the magic is gone. Now I hear those same users say they are "tired of the iPhone" and want something new. If Apple's competitors can deliver good Android experiences, they are going to get to keep those new users for a while.
Not sure why you got downvoted, because you're exactly right: anecdotes are meaningless. In addition, Steve Jobs may be gone, but he reportedly left Apple with four years worth of product ideas, and like you say, iPhone 5 was designed when he was at the helm. The only thing he would probably have done differently is that he wouldn't have signed off on Apple Maps in its current state. But that's neither here nor there.
Unfortunately for Apple, Steve Jobs is dead and the magic is gone. Now I hear those same users say they are "tired of the iPhone" and want something new. If Apple's competitors can deliver good Android experiences, they are going to get to keep those new users for a while.