http://www.atpworldtour.com/Rankings/MatchFacts.aspx
Service games won:
Raonic: 93%
Federer: 91%
1st serve points won:
Raonic: 83%
Federer: 78%
Aces:
Raonic: 858
Federer: 559
Keep in mind that Federer has played 14 matches more.
Aces per match:
Raonic: 15,6
Federer: 8,1
Raonic hits almost TWICE as many aces per match.
Now keep in mind that he is THIS superior, while having only a
fraction of Federer's rallying ability. If the rest of his game was as good as Federer's, his serve would be even more superior.