Raonic leads the tournament in aces and he also hit the fastest serve so far at 143 mph.
Saw him a couple of times on the outdoor courts at Uniprix stadium last summer. One on occasion (probably the hottest day of the summer) all the courts were empty except me for me and my partner and some heavy hitting on the court behind us. Turns out it was Daniel Nestor practicing with/coaching Milos Raonic. The kid has serious talent but like all big kids, he's going to have to work on his movement.
Since that's the national tennis center, I often see Dubois, Wozniak (Marino once) and the top juniors training there as well. The ball speed on groundstrokes is mindboggling.