Excellent song! I think there are top-notch performances all around, great vocals and vocal melodies, excellent guitar work; rhythm and lead, I thought the acoustic parts fit really really well and I like the wah on the lead. Terrific drumming too; solid wall of thunder between you and the bassist, great fills. I really liked the sound of the bass; very nice low end...tight, not muddy, nice tone, too.
Arrangement-wise I liked the change in the middle a lot, and the acoustic guitar just worked, gave it a nice counter-balance to the heaviness.
Not much that I can add to the song to improve it.