watched the camrealabs video and right up .......that what go me think ,
quote from the right up ..
"The choice of head obviously also plays a significant role in the stability of the system as a whole. We chose the Manfrotto 701HDV head (pictured opposite) for our vibration tests, which uses a fork to support the camera plate on both sides rather than just one side on a traditional three-way model. It's not Manfrotto's sturdiest head by any means, but less prone to vibration than most models in general use."
from a vibrations and engineering point of view the ball head design not the best for vibration , ppl spend big money for sturdiest and sturdiest figured some one might have tested it out , because there a trade off
yes did google it , lots of quotes but no details