Sounds alright, felt like it was a bit lacking in frequency variation though. I'm not a composer by any means, but I listen to a lot of metal.
It was a very flat piece, if you can have more deep drum sounds in there and higher pitch guitar riffs it would do wonders for it.
EDIT: Also, I think putting a double pedal in would be sick if you don't have it in there already. The tempo needs to pick up a bit to bring it to life.
But that's just my take on it. Also, the third link was the best of the three. Hope that helped somewhat.