I would absolutely add centennial as a whirlpool hop! I get grapefruity aroma and flavor. I am getting ready to make a clone of Bell's Two Hearted ale which uses centennial exclusively at every stage (bittering to whirlpool to dry hop). Delicious!
centennial is a great WP/DH choice. Centennial, cascade, amarillo, chinook, citra, mosaic, el dorado, etc... are all good choices for late hop additions in APA/IPA's or in any other American style ales.