The question is, Is Volkihar vampirism in Dawnguard the same as the current vampirism?

Incase the question needs to be better explained,

This is almost a asininely stupid but I have not heard or read anywhere that you actually do become a vampire, you only read "join the Volkihar vampires" "become a Vampire Lord" which means the VL form. I am certain you do become a vampire, that would utterly be a epic disaster of a decision for them to allow you to be a normal human out of VL form and not a vampire.

But with how Vampire Lord form itself is labeled as a new class with a perk tree, one would assume this very good question:

What else is new, changed or added with vampirism? A Vampire Lord form with perks is enough for me by far, but what is new about vampirism outside of VL form?