Hey Gav, I had delayed posting on this song until I had watched the movie (which I found absolutely enthralling). I had to buy yoru song. It's now part of the growing Miracle of Sound niche in my computer.
You'rs song is so bond it blows tons of previous official themes out of the water. I've gone back and listened to some of the classic ones and the more recent ones. "The Spy who Survived" really does stand above many of those themes, and I'd put it next to Goldfinger, Tomorrow Never Dies, Licence to Kill and even Skyfall as one of the best themes. It's beautiful. You should let the vocal layering off more often (though I do like the sound of it). Your voice really shines this way.
Yeah, I'm such a Gav junkie by now.