How is a roughing endmill impacted by dynamics?
A roughing endmill, either the corn-cob design or one with chipbreakers ground into the flutes of a conventional endmill serve the purpose of reducing the surface area of the flutes that are cutting into the material. This has the impact of decreasing the cutting forces and lowering the tool point deflection.
Let's say that the maximum depth of cut for an endmill in a full slot is 0.500". The same endmill (same diameter, number of teeth, flute length and stickout) but with chipbreakers ground into the flutes that removed 30% of the surface area of the flutes making contact with the material would be able to cut 30% deeper or 0.650". All things being equal, the stiffness and the damping measured by the tap-test remain the same however.