I too was looking for a suitable replacement for my much loved TomTom Iphone 4 cradle - which was pefect, although only ever used it for charging and the GPS boost.
After many evenings searching, I decided on the this cradle and the Garmin lightning cable (you get a lighter sockect USB charger with the cradle)
As per other comments, this thing is solid - no vibrations what so ever, although it has highlighted a tiny rattle on the iPhone power button.
It's not too bulky with nice looks and good quality overall, not sure how long the retaining clip will last, we shall see.
The only bad point is that the cradle has been made with no tollerance allowance, which means the fit is perfect - too perfect if you use screen protectors. There's no room for the thinkness of the protector and the result is the bottom 2 corners are fouled creating small bubbles on my new protector which took me an hour to fit...
Anyway, I have solved this problem by filing the back edge of the bottom retainers taking a good millimetre off with no detrimental effect to the cradle.