Exactly. Of the so-called "servebots", Karlovic, Isner and Raonic, Milos is by far the most dangerous returner. It didn't show in 2015, but if he starts winning around 20% of his return games, he's going to be dangerous as hell. He was at 16%, I think in 2014. Somewhere around there.
He actually is the model of the next generation of aggressive players, over 6'4", with a 2HBH but a good slice one hand backhand, huge forehand, and he wants to get to the net. It only takes one great player to take over the tour, and sooner or later we are going to get a guy like Raonic who is also faster. The way to get to the net has always been to get weak returns, so today in order to get those weak returns you need a first serve around 135 mph, and a second serve more around 120. Well, that's starting to happen.
Plus I just don't think the very best 1HBH holds up against the best 2HBH, so anyone who can hit with two hands off that wing and can also hit a good slice is the least attackable. If that guy can also rush the net, that's the way to go, it seems.