Is a decal cheaper than one plane with a texture?

In my game performance is very important and i will be using blood for the dead units.
Everywhere i look it seems decals is the way to go for this. However, i was wondering if it is really better than just a plane with a texture.

How can decals be cheaper than a simple plane especially if spawned as an instanced static mesh?

Doesnt the decal still have to calculate and adapt to the surfaces where its projected? Whereas a instanced plane seems to me to be more simple than that?
bump

Bumpity bump? BUMP :smiley: