Just wanted to confirm it - I have also updated to KitKat and the issue is still there (while speaking on 2G).
Moreover one of the Moto G's has a fault, that when you call it, you can hear yourself (echo). The problem is much worse when there is silicon case on it and almost non existent while there is completely no back cover.
It seems that the microphone on it is much more sensitive than on the other 3 - even if I touch the phone slightly I can hear it clearly in the call. When I do the same with the other three nothing is heard.
If anyone has an idea what this could be caused by (probably faulty microphone/audio tunnel) I am open for suggestions