I wasn't entirely sure, but I kind of figured that their brain tissue would have to remain in order for them to still be "Cybermen." If they were entirely artificial, they could simply build new Cybermen from scratch and not bother converting anyone... then they'd just be "robots."
gbollard wrote:
One of the biggest differences between the cybermen and the daleks is that the cybermen were constantly evolving while the daleks hated anything that was different - even "evolved" versions of themselves.
Yeah, the basic appearances of both the Daleks and the Sontarans have remained pretty consistent. But the Cybermen keep getting redesigned, sometimes within the same Doctor era. The longest time they stayed (mostly) consistent was during the 80's. And now they're not from Mondas, or even the same dimension anymore.
gbollard wrote:
They got rid of the moving chins quickly after earthshock because they had problems with the props.
Probably because they would've been harder to decapitate.