This. He seemed a 25 years old guy today.
Fed is still great when he can attack freely, and he could do that today. But like BroTree said, this means very little going forward because Janko can't force Roger to defend like for example Delpo can. And it is in defense (or rather, the transition from defense to attack) that Roger has declined the most.
"Certainly the most talented individual, the most well-rounded
... to play this game." - Jason Goodall
We should be appreciative of Federer though, because we will never see anything like him again. The fact he can still compete for slams ever after the erosion of his physical skills is really a greater testament to the natural talent he has than the period of time when he was dominating the tour.