Pretty fucking nice instrumental.
Don't have much to say, actually. It's like, it's fucking awesome, and it leaves me with nothing to say :P
There's some really, really minor quibbles with the mixing in my opinion. So minor that those could be taken as artistic choices than minor mistakes. However, you should have panned the riff guitars to the two channels to have it as stereo. That way it would have sounded more filled, and still would have left enough space for the leads to play in the middle.
It's awesome, and one of the few songs that I have favourited over here in the Audio Portal. Keep it up.