I have a FLM Centerball 58FT. It's this one: http://www.fotomayr.de/webkat98/home...tml/001906.HTM
It has an adjustable friction as well as a tilt lock. If locked with the camera adjusted horizontally you then can only tilt the camera. This way you get the best of both worlds. The 58 in the name refers to the diameter of the ball. So it's pretty heavy.

Ulrich