I think the meaning of High Concept has changed over the years. It used to be a clever twist\story or big star, but now it means ---- drum roll please ----

Will my kids like it?

Transformers, Avatar, Iron Man, Dark Knight, all great stories but all very accessible to the under 18s.

I think high concept means what it has always meant. Can you tell me what your story is in one sentence and that sentence will get me excited enough to read/see your script/movie.