Ahhh, sorry about the wrong word. Should have caught that.
But to be clear, yes, I meant it is better to render an object directly in the scene rather that to composite an object in later and try to match it up.
So even if dealing with 25gb object sequences is difficult to move around, the lighting and shadow the object interacts with in the scene is going to be more correct than any composite. Thats why I am a fan of the option to use object sequences.