I've heard about the possibly of Auto-Tune, but the way he sings it live seems about the exact same, so I haven't read too much into it.
It seems like his voice is really the deciding factor, from what I've seen on comments of the album. I'm personally still working on picking favorites off of the album and whatnot, so I couldn't really recommend much. His voice is pretty much consistently like that, though, it jumps up and down a lot. His previous albums might be different, though I've never heard them.