From one metal artist to another, this is my review:
The actual structure of the song is good. I hear plenty of room for badass lyrics and shear power.
However, given all the excellent plugins you are using for the actual metal aspect (SD w/ MF expansion and Amplitube 3), you have some work to do on those sounds.
Drums:
The kick was all treble, no bass, and had that boxy sound. The snare is alright, but needs more presence and low end. The cymbals are almost spot on, maybe push them back and to the sides some more.
Guitars:
The guitars had a LOT of buzz and had nowhere near enough dimension to them, and it sounds like you have the gain and distortion all the way up on it, which doesn't help. I couldn't really make out separate notes. If I may, I recommend you get Le456 and LeCab (free VSTs, Le465 is an incredible ENGL emulation, LeCab is a cab emulator) and get God's Cab 1.4 (free impulse files for LeCab, has many different mic/cab/placement/distance impulses). Both LePou and God's Cab team did an awesome job and I think you'd get a better sound from those.
Orchestral:
The theme is good, but in MDM, the symphonic parts are usually in the background of the song while the actual metal sections are the focus. Expand the dimensions on those to push them to the outside and the rear a bit for more depth.
For a work in progress, it's coming along nicely. Put more work into the actual sound since you have the writing down for the most part (I'm guessing this isn't going to be a 2 minute song en totale). I'm interested to see what the lyrical and vocal theme of this piece ends up being.
If you need some help with SD, I have a few home-made presets you can use/play with. I think they'd give you a good basis for a solid drum sound. If you want them, send me a PM. I'm happy to help.
Keep up the good work!
-Tim