Hm ... the phone is indeed securely fixed and no scratches in the holder and is also easy to remove. But firm grip looks completely different. I fluctuating nachwievor use and replace between further. Because there is a holder, which is a bit more expensive, but not so shaky is (from Wicked Chilli Design Car Mount Holder for Samsung Galaxy S4).
In the just mentioned can also fixed in comparison to Mumbi via a ball joint. When rated here Mumbi serve only 2 detented plastic knobs to align. This unfortunately is never 100% fits the way you would like.
Positives:
The shell is upholstered back
The suction cup has never gone off me and therefore holds very well
Inserting and removing is well and safely solved
Cheap (not cheap)
Negatives:
everything else
Conclusion:
For me it is still acceptable, this shaky, vibrating bracket continue to use even if it is inspiring little confidence. I use rarely the Navi on my S4, but this be connected to the FM transmitter / Handsfree. But that's still okay because I have rarely touch on the display. Who but a lot with Navi runs on the phone -> hands off and buy the thing from Wicked Chilli.
Had 2.5 star possible, then I would have given this. More that thing does not deserve this.