For the past 1.5 years I have streamed an old time radio show from Safari while walking my dog. I do this while using Chrome, Twitter, Facebook, and other apps simultaneously. I have never once had the audio drop out on me. Yesterday I did this after picking up my brand new 128gb 6+: I listened to audio on Safari while using other apps. My audio proceeded to cut out no less than two times as Safari was purged in the background. To reiterate, this never happened once in the hundreds of times I did this exact same procedure with my iPhone 5. I don't know if it's because the hardware now has to drive a massive screen, or if it's merely iOS 8 teething troubles, but this is a very real problem right now. I love iOS for its rock solid dependability, that you can generally throw anything at it and it just works. Right now that is not the case.