I would think hard and rough also. Smooth and gentle can be applied to every woman out there but the chances for hard and rough fucks is not always an option for many. Of course the black guys chances for applying the rough fucks with most all the white females are pretty good. Much higher than the white boys chances at pulling it off without injury to themselves from the white girls who won't put up with it.
The majority of white females that are and will give that white pussy up to the black guys are submissive sexually to the black man so this makes it fairly easy for these guys to do as they please so there would be no real reason for them not to take advantage of the rough fuck opportunities each time they fuck the white girls. I feel pretty sure that is not the case when they fuck their black females because I don't think these ladies would allow it.
I would think it all depends on the mood but my wife likes it hard and rough most of the time when we play with other men. She likes to be taken and since she's submissive its up to the guy who is fucking her.