While I fit the C-PTSD model, I think, subjectively, I'm not sure yet if there is a significant enough divide between PTSD and C-PTSD to merit it's being in the DSM.
Some have said (online, not here in the forum) that one gets Dx'd Borderline if the T. doesn't "like" the patient and Dx'd C-PTSD is s/he does like the patient. In other words, it seems unscientific to draw a line between Borderline and C-PTSD based on rapport or personal chemistry.
More to the point, I don't agree that C-PTSD merits a special diagnosis in that it is still just PTSD that ensued during childhood and disrupted the development of certain emotional resources, such as trust, communication, beliefs about self and world, authority figures, the "system" and self-protection measures, or "learned helplessness," Stockholm, and other problems.
I think it has most to do with age of onset and what was supposed to be happening in our society for a child's "normal" development at that age. Throw a lifetime of PTSD suffering into play with that, and you have what they call C-PTSD.
What is helpful is for clinicians to not downplay the significance of doing everything to build trust, and to be willing to do this, every single session, if necessary, only to be rejected for transference reasons, nearly every time. That is usually noted elsewhere, not in the criteria above.
I am one of those who is severely trust-challenged. I see a dark shadow over every person in a position to offer me assistance. I know I'm perceiving a darkness when it emanates from within my own consciousness and perception of the world, but, as stated above, that has, unfortunately, often been accurate. In some rare cases, I don't want to stay and find out. I'd rather leave and let it remain a mystery if that person was, indeed, dark at the core.