The huge difference: I became a Dream Theater fan during the current line-up, that makes them the only DT for me, for me this is Dream Theater and the previous versions of Dream Theater are in the hisotry books, , now if it happens that someone changes now; I'd surely get banned heh
But in Jason Newsted or David Ellefson's cases they were part of my bands identity that I came to love, I don't give a flying potato fuck if their replacements were Gods of their instruments.