Excellent sound! Soft vocals against rough instrumentals. The contrast works extremely well. This is all what I have to say before checking out the source song, which I've never heard. Time to go check that out!
After listening to that, I can definitely say your additions make it a far catchier song. The original also uses the harsher instrumentals in a few points, but is more often a softer song. Still, I can see where you got the idea to expand on the sound that those parts of the song started to create. You took them and made them bigger, better. Well done, man! I'd expect nothing less. :)