Well, lets just break down all around and overall as words before we apply them to freestyle. All around would mean every aspect of something. Overall would mean every aspect of something. They are the same thing.
I understand that many freestylers think of all around as someone that does lowers, uppers, sits, and maybe grounds. Really, it might be better to just say well rounded. All around will include things like flow, showmanship, difficulty, creativity, variety, etc.