Use the bracket with a Moto X (2013) and can confirm that the seat in the "bracket" absolutely is fine - even in heavy jerking. But just as even steps on the mentioned in the headline problem: Due to the long and flexible gooseneck the fixed phone must necessarily lie somewhere on the faucet. Otherwise wobbles and swings the free-hanging mobile on normal road cheerfully to himself. On some rough road you can then almost get scared.
Conclusion: The holder is super processed and used flexibly basically - but the long gooseneck leads free suspension to greater swing. A rest on the armature is thus highly recommended. Those who show has no way should perhaps resort to another product. Otherwise I can recommend because of the high quality production, the simple but sturdy clip and the really very strong suction cup.