I was not sure about these magic arms from Manfrotto but I chose to get one of these on the basis that Manfrotto seem to know what they are doing. In this case, they certainly do! They are simply amazing, so much so that I now own two of them.
They are quite heavy for their size which would relate to the quality of the materials used in their construction. Paired with a 035 Super Clamp and a 143BKT Camera Bracket , I now have a very versatile mounting system for my Sony HVR Z1E (an old but still very capable camera) which it holds with ease.
A worth while investment for anyone that needs flexibility when mounting a camera instead of using a tripod.