I'd say this is an 8.5/9. I've really been in the dumps-ish area, and this sounds like the right song to chill to. I could definitely listen to this in my spare time; I really like songs with a mellow tone.
Edit: Gawdamnit Billy, now I gotta listen to that, too.
Right now, I'd give it about 7; I'd add it to a high-octane playlist for my video games, for sure. (Kinda reminds me of when I used to play Art of Parkour.) If there was any little thing I didn't like about it? Eh, just the repetition, but that's no biggie, repetition does well here.