Thanks for the note; I never understood what would make the difference between 75 vs 100.
They also have the aktiv10 with a 100mm, but it has the same payload.
I've filmed with an Sachtler FS8 using a Panasonic HPX3000, Fujinon lenses, and Anton batteries, it was a little bit of a pain to keep balanced at times, but overall it worked. Other than balancing, I am not sure what else would be the issue -- perhaps stripping the fluid head overtime?