I normally see "heady" used to describe a pleasant scent, and I normally see it when I am reading books. I rarely hear it out loud. Perhaps if I worked in a perfume or candke store, I would encounter it more. :) I have never heard "heady" or "headiness" used any other way. For anger or a short temper, I see and hear "bullheaded" used often. For reference, I'm in the USA.

Not used very often, but regardless of the dictionary, the two main meanings are "intoxicating" and "rashness" The headiness of his scent was captivating. His headiness got him into trouble again. (more common use) Hope it helps!