i like what you tried to on the intro, but i dont think that the instrumentals come in heavy enough. try adding like a bass drop, but dont make it so noticible it sounds like youre following the fad of adding ridiculous bass drops to anything closely resembling a breakdown, but one subtle enough to help it come in..
id also search for a meaty-er kick, IMO i like kicks that dont click as much, but instead back up the guitar chugs and adding body to them rather than shining through the mix, but that is subject to taste