It's cool, but the placeholder vocals kinda shit it up for me. They're really monotone and undynamic, and I think they fuck with the perception of the mix because you've got this really solid, dynamic performance with lots of movement under it and it just doesn't fit. It's the audio version of a medium rare filet mignon covered in ketsup - there's obviously great stuff under there, but you can barely tell for the crap on top of it.
I think you should just do your own vocals. Cover them with reverb and distortion and bury them in the mix if you have to, but at least it won't sound programmed. The problem with this whole process is that eventually someone's going to sing over your stuff (you or whoever) and it's likely going to end up being wildly different from a sonic viewpoint by virtue of being a real human, so I'm not sure the placeholders are doing you any favors. Or someone isn't going to sing over it, in which case you're wasting your time and should be finding new and interesting ways to fill that sonic space.
Have you tried getting ahold of Stapp? I hear he's got free time these days..