Perfectly summed up. His racket head speed back in 2005 was impressive, one of the loosest arms in tennis history.
As for the serve, I've heard before some people who think Fed's serve nowaday is better, seems like McEnroe thinks his way too.
Don't quite agree, Fed's serve certainly changed over the years, but not necessarily for the better. I don't think Fed is nearly as clutch on his serve as he was in the past, today he almost can't buy a serve to save his life once he's on the ropes.
Fed used to be a great server in pressure times, and that element alone is of adamant advantage to vintage Fed as opposed to the Federer of the last few years.
He may have served more aces in the last couple of years, but one thing is to serve aces on very unimportant moments like he usually does now. Another is to summon all these aces and this serving capability in the moment where he most needs it.
Look how many times Fed's serve came to the rescue on important moments in the past:
http://www.youtube.com/watch?v=NJc_lQ0LP50
www.youtube.com/watch?v=kad5tG3q2Rs#t=1m26s
www.youtube.com/watch?v=hfb2PDlIc3o#t=4m53s
http://www.youtube.com/watch?v=LTvGt07DXfQ
Look at the caliber of most of these returners and the importance of the moment where he is pulling all those aces...
It's unfortunate but I don't recall Fed doing this nearly as much in the last couple of years.
Oh, in addition, Fed's return game was MUCH better around that time. If we look at the statistics post-2008, we see that what has fallen the most was his return game. If we watch the clips, the difference in footspeed, footwork and movement is clear, but pay attention to the kinds of returns Fed was making in the past.
Really underrated returner in the game.