Sorry! Whew! Calm down there, son!

OK, I listened to them both, and I would definitely say that your vocals are better. Duncan's vocals are probably technically better, he has a larger range than you and whatnot, but the tone of his voice is not at all interesting. The version with your voice has a little more "mystery" to it; it's just simply more interesting to lsten to. Perhaps because he didn't write the lyrics he wasn't inspired to put meaning into the words.

Anyways, my vote is for your vocal version, and it's a hearty vote at that.

Oh, and a little note, although you probably won't end up doing this, I would add a little more buildup to the outro solo, maybe like a little drum roll or something. Other than that, the song is pretty cool; I like it much better than when you posted it the first time (probably a year or so ago).