SEO PLugins - Duplicated info ?

Hi

For example on a post or page admin screen you could have three different boxes from say Atahualpa, then All in One SEO and Headspace 2 for SEO data.

I guess you only fill one out, as this woud be duplication of titles, description and keywords. Is this correct as I just wanted to confirm this either way.

Not sure if to delete Headspace 2, unless its useful elsewhere for SEO.

Any links or tips would be most appreciated.

Many thanks