Everyone seems to agree that Federer has a better return game than Sampras. This is because Roger broke serve more often and easily than Pete.
However...
Federer mostly blocks back big serves and then uses his dominant forehand to win the point. That is how he breaks opponents. Sampras also mostly blocked back the big serves of his opponents.
But Pete's opponents followed their big serves into the net to put away easy volleys. Federer's floaters would have been crushed by many Serve/volleyer opponents in the past.
Thus if Roger played in Pete's era, he would not have broken people as easily as he does today.
Roger breaks opponents more with his mighty forehand, than with his actual service return ability.
However...
Federer mostly blocks back big serves and then uses his dominant forehand to win the point. That is how he breaks opponents. Sampras also mostly blocked back the big serves of his opponents.
But Pete's opponents followed their big serves into the net to put away easy volleys. Federer's floaters would have been crushed by many Serve/volleyer opponents in the past.
Thus if Roger played in Pete's era, he would not have broken people as easily as he does today.
Roger breaks opponents more with his mighty forehand, than with his actual service return ability.