In this related question: Slinky base does not immediately fall due to gravity
It is observed that the base does not fall immediately.
Obviously the center of mass is in free fall, and the tension of the slinky initially pulls the base up. My question is:
Does these forces cancels exactly so the base is really stationary (independent of slinky properties like mass, spring constant, ...)? Can this behavior be seen in all springs? How long does it take for the slinky to collapse?

(image copied from the other related question)