Authors & Readers: how well do you "see" the character?

I was struck today, when I was listening to THE SKULL BENEATH THE SKIN by P.D. James, how intricate and detailed the description of the various characters was, right down to the frown marks between the eyebrows and the slightly thick legs.

And I wondered how many people are like me, and usually have only a vague idea of what a character looks like?

I wondered, if I was a writer, whether I would bother to draw a stick figure with major characteristics marked in, or whether I'd even go as far as getting an artist to draw a rough sketch.