I agree with Andres, I see no difference.
http://www.youtube.com/watch?v=FoMBxY7hgcQ
Until 2007, Nadal was losing to journeymen
everywhere on hardcourts, except for the slow hard courts leading into the claycourt season. These slow high bouncing hardcourts were the only place Nadal could transfer his clay court game to.
Then the AO was slowed down, then the end of year World Championship was slowed down when it moved to London, then all the hard courts leading into the USO were slowed down(remember how unbelievably fast Cincinnati was?), then the USO. What little indoor tournements are left are all ultra slow.
Nadal has only ever been able to play on ulta slow high bouncing courts, and in the last 5 years virtually the entire tour has been changed to his preferred speed and bounce height, except the French which is actually faster.