apparently he is a soft player and doesn't have great wheels.
Watching highlights of his goals it looks like he has pretty good wheels to me. There is one goal where he scores against his old team the Wings. They turn the puck over to him and 4 wings chase him from their opposing blue line all the way down the ice and he pulls away from all of them for a clear cut break away and a goal.
In other highlights on the PP his lateral speed and mobility look very good as well.