Dude this is good. Very exciting to listen to, lots of variety to keep it interesting and still has some consistency. I absolutely love the breakdown sections and the way you bring it back to the dubstep sections. Sometimes I want to make a song like this but for some reason I can't really get it right, but you nailed this.
One thing I might change is have a pad through at some of the more sparse sections to give it a little more body.
Cockadoodledooo