Fed is definitely more pissy now than in 04-07 for example.
More often you will hear "Oi!" or grunts of disgust at another shanked backhand, or a yell here or there. And when is "calm", you can even sense on his face that he is fuming underneath.
Djokovic, even in 2011-2012, I am still seeing anger, points of disgust, yelling after missed shots, destroying a bench at the RG final, etc.
Does McEnroe want them to do what he did where every call is a cinema trying to influence the linesperson to change his call? Does Mac want them to berate themselves like Murray? Borg's book, Bjorn says when he was playing, he was calm outer, but he was absolutely destroying things inside.
Doesn't he say "Nein" when he shanks backhands lately?
Anyway I think showing a poker face it's a great advantage in tennis. I've heard many Fed's opponent mentioning that not seeing him angry or upset when he's losing makes them nervous cause he seems to be always in control and ready to turn around the match.