Which portions specifically? Gave it a listen and didn't find any parts that came close to not sounding robotic. Maybe in comparison to the other examples linked here, that one was better (but I'm unsure if that's actually true), but if that's state of the art, I'm not sure it really comes close to hitting the mark.
Definitely not state of the art as far as being humanoid, that would be the top level link.
It's also not particularly humanoid, just closer than most vocaloids I've heard. Going off of my memory of the song, it's more the intonation then the timbre that stuck out as being more realistic.
I'm afraid I'm not willing to listen through the song currently, I usually dredge up some stuff I'm not wanting to deal with right now when I listen to this artists music.