the achievment that sets Fed apart from Agassi/Nadal's career slams is the fact Fed has reached all 4 slams finals in one calender year - THREE times
no other man has done that since Rod Laver in 1969
you could argue Fed's 4 slam finals, 3 times in 4 years, is better than Rod's 2 grand slams.
I agree that this is very impressive, regardless of the ear
. It´s especially impressive that he managed this in 2009, when most would agree he was no longer at the peak of his powers...
But this is a different achievement than a career slam, which Federer shares with both Nadal and Agassi.