I'm 80+% gray and the hairs did come in coarser, more wiry. They needed about twice as much conditioning and moisture. Once I learned how to care fort them, they are good to go.
My blog - http://suburbanbushbabe.wordpress.com/
My FOTKI - http://whatsnew.fotki.com/suburbanbushbabe/

Playing with my hair is a hobby. Fluffy, fine natural 4a. Goal= Healthy, beautiful hair that retains its length.
Hear that crash? It's me falling off the CG wagon.