Hello,
I'm listening on my iPad so I won't say anything about the mix. As for your arrangement, I would definitely not have the lead synth playing throughout the whole track. You got to put in a nice rest to set in some dynamic. Otherwise, it gets a bit boring after the first couple minutes. I'm not a dubstep fan so I don't really know what is the main arrangement style for it. But I am a big trance/techno/dance/electronica fan and even for the hardcore tunes they will usually always have a rest bridge with soft-synths in which it'll be calmer and allows the listener to "rest" before the hard synths and pads pick up again.
I hope that helps. Remember, use dynamic to avoid a monotone mood.