Not sure if you guys experienced this, but before Touch ID days, especially with iPhone 4 and iPod Touch 4th gen, I would often hear about people's touch button stop functioning and/or pressing. This seemed to be a common issue at that time. I personally had it on my (iPod 4, iPhone 4, and iPhone 5). Does this issue still occur with newer iPhones (not X). I would not suspect it should affect the 7 or 8 series since they use a haptic engine (correct me if I am wrong). But does this still occur commonly on the iPhone 6s/6/5s/SE? Just curios, if the Touch button stopped pressing on an iPhone with touch ID, would the sensor still read the finger print or does the entire unit stop working?