Don't get me wrong, I really enjoyed the ending. But I think there should have been some warning that all the fetching and getting before you get into the Forbidden Zone was the whole of the DLC. On my first play through I was expecting that all the fetching and getting was in preparation for a big giant series of battles in some multi-level bowels of the Forbidden Zone. One giant robot scorpion in a big room? That was it? On my second play through with a character with the Robotics Expert perk I simply snuk behind it in the stealthsuit and disabled it. End of story.

Is there such a thing as DLC's for DLC's?

Yeah, it is a bit anti-climatic though you can initiate battles depending on speech choices after the giant scorpion.

I don't recall that in the advertisemants.