"..."
It's definitely a personal preference, I get that.
Can you hear the 'but' coming?
"..." while useful, in severe moderation, can be a good 'dialoge' indicator that the speaker is either caught with nothing to say/add/comment or sometimes to imply he's confused about something, overuse within a fic will make it look as if you, the writer, are at a loss as to how to convey those moments of speechlessness or confusion.
Ummm...maybe it's just me but if you're a writer, write? Set the scene, convey the feeling of not knowing what to say or do or think or feel. Grab me by the short hairs and really make me feel it using the tools you have at your disposal. You know...words.
"..." does not do that if it's used more than once or twice in a fic. It's effective in humor/comedy fics/situations. Certainly not in a dark-themed fic where you have one character forcing himself on another.
Frankly, I think it is lazy. Could be just me.
I'm not saying don't use it, although I would use it sparingly in the course of my writing, if I used it at all. Just use it to good effect, once in a fic.
Overuse it and I'm rolling my mouse to the back button.