Your intro is great, but there is some work to be put in your dubstep. Low growls are very efficient, but only when used effectively. You had a smooth debut which you then obliterated with a SAVAGE drop. When I say savage, I mean it. See, when it's not dubstep, it sounds really nice. There's an atmosphere going on. But you need to be very careful. If you would've implemented some growls in the build-up, kind of as an underlying tone, it could've been much more efficient, and less of a jump to something much more brutal.
Also, tone it down a little in the dubstep parts. Something that is too aggressive can be unpleasant to listen to. If you don't want people to tap out of your songs, dose it.
Overall, the track sounds good, but you went a bit too wild with the growls.
Hope you can use this critique to perfect your art.