If he holds, it holds well.

But only then. Placed on a cold windshield in the car - no chance drops out immediately again.
If the disc is slightly warmer and slightly curved, the holder attaches itself superfirm - he even stay tuned on potholes.
The arms can be adjusted well and have a fine set of teeth in the joints.
Thus they hold exactly in the desired position and do not move.
Use it from time to time in the car with a GoPro. You have to try but about 20x until it finally stops.
Others can do better holder.