[Suicide Junkie]

A null space PDC is exactly the same as an All-Shield-Skipping PDC.

Armor-skipping PDCs are pointless.

Units don't lose components, the entire vehicle is either alive or dead. So there is only the shield part, and the total hull hitpoints (comps + armor).
A crystalline shard for example, will normally destroy internals first. But, a fighter dosen't keep track of components, so if it was damaged to 109/110 hitpoints, it would have all its guns/engines/etc working. The armor-skipping weapon has no advantage against units, and acts exactly like a normal weapon.

Anyways, what I'm trying to say is that a null-space PDC and a shield-skipping PDC will have exactly the same effect. So keep whichever looks/sounds the coolest, and drop the other. OR, make them different somehow (range, damage, accuracy bonus, etc).