Well I must admit that it is a bit more complicated than I had thought! I do dislike being told that an aircraft is "2000 ft below" when I am in descent, because I suspect that I was higher the last time the ATCO looked at me on her radar screen, and therefore the other aircraft isn't 2000 ft lower at all.
It is the uncertainty that I don't like, and I'd certainly feel happier if I was told that the aircraft was "at 3000 ft" whether verified, unverified, or "at". Then I would feel I knew where it was, +/- 200 ft or so.
However I am not knocking the service, which is usually very good and only making a pilot's subjective comment. Not many other pilots have joined in with my view, so maybe it is not widely held.
I do feel that we sometimes make quite odd changes to the way things are said because "something once happened". I know we have to learn from experience, but I feel we do rather overdo it at times.