Right now the 3 "sustain" cp only benefit your regeneration while you have siphoner on the other hand which reduces every resource gain be it from armor, passives, regen or potions.
For other cp the counter cp does exactly the same thing as the offensive cp.
Hardy and Mighty ~ 15% increase/ decrease for poison, physical and disease damage
Elemental expert and elemental defender ~ 15% increase/ decrease for magic, fire, frost or shock damage
Bastion and Shattering blows ~ increase shields & increased damage against shields
Etc.
This is why healthy, Arcanist and mooncalf should also increase your resource gain on sets, potions and passives for the respective resource
No increase for heavy attacks as we still have tenacity cp
For the record, i'd like to see both poisons and siphoner to be removed but i don't excpet this to ever happen