I used one of them on my Expedition, as I was trying to find anything that would fit on the passenger side mirror. It did vibrate quite a bit. I also had problems with them staying on after about a year of usage. If the mirror was slightly dirty, the suction cut wouldn't get a good vacuum and they would fall off after a couple of miles. Make sure you use the safety strap in case that happens. I even had it fall off once when the temperature warmed up 20 degrees after about 4 hours of towing.
The other problem I was having was that each time my wife would get in or out and close the door, I would have to readjust the mirror. This was not a major problem, as the power adjusters would move it, but it was something else had to be done.
They were indeed adjustable from the inside of the vehicle, and that was useful sometimes to double check exactly where the tire was tracking (to avoid some object - usually at gas stations or campgrounds).