This is a good sign that the dubstep genre on newgrounds is coming back from the 'no flow, nothing but drops' craze it has had in the last year. At least in my experience that is all I have mostly found on newgrounds for dubstep. So to the real review.
Great job, this is actually a really good sounding song. Only trouble I heard was that there was a sort of jump between parts like 2:56-3:01 that made it sound a bit like the song skipped a note or something. A bit repetitive here and there.
Also, that sample you snuck in at 4:37 was pretty nice, so good job!