Well, I don't feel qualified to judge a quality complete mix like this, but geez - no one else is commenting, so...
First of all, I agree with everyone you've shown it to: I was bangin' listening to it, especially during the fast parts. Interesting arrangement in that the fast parts are all in the first half of the song; I'm wondering what the song is about and why you chose never to return to the speed again. I'm assuming that the subject matter warrants/necessitates the shift.
It's got loads of power and overall a good mix. It starts to sound KILLER (at least to my ears) at around 1:30. The harmonies there work really well. Well done. I like the lead tone and the solo at 1:54 is creative - I liked it and it accentuates the song in a bizarre/good way. All the harmonies work well throughout the extended slower part.
The only thing I would maybe consider working on would be the tone shape of the palm muting. On my computer speakers, it sounds muddy and on cheap headphones it sounds kind of shrill and loose. It might sound perfect on good speakers but not everybody listens with good speakers. If you were going for that overloaded power-over-tone feel, you achieved it and that's not necessarily bad, but I'd like a little sharper/tighter feel to the palm muting.
Overall, very good.
