Although I'm not particularly a dubstep fan, I found this track very enjoyable. The way you switch back and forth between the dub style and the trance-like bits is well done. The bits where the switch is quickest (one such section starts around 2:50 after a moment of just guitar) are, in my personal opinion, the best sections of the song.
The mastering is done well, and nothing is too overpowering. I would've like for the guitar the be a bit louder, and perhaps glitched a bit (which is easily done through programs like Image-Line's Gross Beat). However, that is again a personal preference.
I liked your choice of synths, and the higher ones in particular. The bass felt... Stereotypical, though. Cliched, even. It's the same bass I hear in almost ever dubstep song. Perhaps a different waveform is in order (has anyone tried making a dubstep bass out of an organ)? Although that didn't detract from my overall enjoyment of the piece.
Your choice of chord progression was nice, and added a bit of umph, if you will, to the flow of the piece.
The buildup, while short, was well suited to the song. As was the ending/outro.
All in all, a well put together song. 5 of 5 and 4.5 of 5. Looking forward to more.