A course of action becomes clear
Overall I think the song is good, but needs a better mix.
The scream at the beginning lacks intensity because of how it mixes in with the song. Maybe increase its volume as the scream opens up. It's a really good scream.
The hi hat and cymbal hits sound too quiet, while the kick drum sounds a bit shallow/flat. It also sounds that you have the cymbals panned a bit too hard left. It's hard to tell with my very old boom box, but look into that.
The death vocals are good quality. The clean vocals lack in strength. That's partially how they're mixed (softness, dryness, maybe lack of some dynamic effects) and how they fall off pitch a bit. I know your dead set on not using pitch shifters, but it's okay to use them to correct small errs. It has nothing to do with current vocalists comapred to those of the past before pitch shifters were available; even the greatest of singers fall off pitch sometimes.
The bass guitar gets too loud at times, like in the end, and at the end it seems that something is falling off time a wee bit.
The guitar solo lacks sustain it needs (or something during the hammer on/pull off parts mostly), and I'm not sure the effect (sounds like an electric violin?) on it blends in with the song well.
Again, overall a good job. The song has a good flow that carries the listener through. I think if the mixing was upped a bit, then this song would kick a little more ass.
So an 8, to leave room open for corrections.