It's proper, hauntingly atmospheric, meditative and gloomy mood music that allows you to take as much out of it as you want: a perfect soundtrack for dark days and long sleepless nights. The best way I can think of describing music like this is "loud ambient" - essentially it uses the palette of modern metal to create sonic spaces that work equally well for immersive listening or as background. If you like this, definitely check out Insect Ark's brilliant album 'Portal/Well' which is what 'Nessun Luogo' reminded me of most strongly.