This song was an instrumental experiment in mono, I wanted to attempted to reach a more minimalistic approach to mixing. While stereo appears louder, mono is often a lot easier to mix because you get a much wider panning ratio. I also find it easier to mix guitar solos in mono, they always come out more clear even with heavy distortion.
I think in the future I'll continue to mix guitars, bass and vocals in mono but keep midi instruments in stereo like I was before. Sometimes midi instruments like drums, strings and piano can sound to thin in mono while guitars and bass can get over powering in stereo, at least to my ears they do.
Anyway that concludes my little mono experiment, I hope you enjoy.