I find the word survivor patronising for some reason... I don't know why. I have said both terms, it depends on who I am saying to and what I am trying to say. However, I do notice myself tending to just say "I have PTSD". As much as it may not be true, saying sufferer or survivor for me seems to say that it is all encompassing who I am and I resent that...So I tend to say I have PTSD. Because I also have a personality, and have other things. Like somehow it doesn't sound so definitive. Just my personal opinion, I'm not hugely offended if someone says "you are a sufferer/survivor" or anything, just personally prefer to just say "I have PTSD" myself.