Fantastic video-gameish metal
How you used Slayer makes it sound less like like a real heavy metal, but rather a video game song, something you'd find on Megaman perhaps? Anyway the only thing wrong with this is Slayer. The melody is just GREAT but it is brought down by the overall crap quality you get from Slayer. I suggest you get RealStrat with the Amplitube 2 VST. Really real sounding guitars, but really the best sound you can get is by simply recording live guitars.
Anyway, awesome piece!