I haven't noticed any serious problems on my 5S or my Air yet. But to be honest, I haven't had a huge amount of time to use either. I'm about to head to Starbucks for some reading (need to re-read "Mockingjay" before the movie comes out :) ), and I'll probably play with a lot more than I have had the chance to so far. So, we'll see.
But so far, so good.