Issue with comments like this is that many folks, I would dare say most, skip over the parenthetical and simply believe that if they don't like the way it works then it is defective and give them a new one. Doesn't matter that it's within spec, or that the tests say there's no hardware issue. Many folks think those tests are fake and are designed so Apple can say tough luck etc. People just refuse to believe that leaving your bluetooth setting on when it's not anywhere near your car could drain your battery. Same with poorly written apps, same with being in an area with crappy cell service (which can make calls sound like poop etc).
This is the dark side of this tech being in the hands of folks that have no clue and don't want one about how the tech works. but they are quick to demand a new one cause "I spent a lot of money on this so it's going to be perfect"