Good performance with errors

Now Since November I have been working with the iPhone 6. It is now my fourth iPhone, that is, I am well acquainted with the operation. The again enlarged form would have Apple can save me; the 6 Plus comes for me not in question because it's really too big for a mobile "phone". Basically, the iPhone seems to 6 therefore come with the usual Quality, but also with the usual pitfalls. Although I am an avid Apple user, I sometimes seem to myself ver-Appelt. So I have had from the beginning of trouble with the touchpad. Sometimes I have to press several times before the entry is made. Especially the letter A in requires more than 50% of cases entering a 3 to 4 times Press before the letter finally appears.
I have the appliance eventually returned to check by Apple, which all went wonderfully simple and fast. The device was picked up within a day by UPS and was after 3 days again. Unfortunately without any repair, because allegedly the fault would not be reproducible and the device had passed all the tests. In the local Apple Store the error was Auber by the owner very well reproducible! And it still exists. Although it is not much of a problem, but for a device that is nearly 800, - Euro costs, an entirely unacceptably mistake! Therefore, I only 3 stars.
Quo vadis Apple? Reliable quality once was?