I just bought another manfroto 190 ... my old one was great, this one sucks. There is a new 'snazzy' stem that comes out and then drops to the side. The section where the head joins on looks like its metal, but its actually plastic.
my LF camera is like a 20Hz tuning fork prong on it. Sure its stable but shit it wobbles.
My solution has been to run a drinking straw (no kidding) from the front standard down to one of the legs and use a blob of blue tac on each end to 'attach'. This seems to nicely dampen out the vibrations. I liked the idea enough that I now run another straw between front and back standard for extra stability on my Toho camera.