Great stuff. I think you're pretty much done with this mix. Just your little touch ups and fx if you want and hopefully it'll be submitting time! =]
Edit:
I think that its fine to have one robotic and one natural, but if you do, I think the male vocals should be more electronic/robiticized than it is right now. Like techno or trance male vocals. For Melinda, personally I would like to hear some sustain/reverb on her vocals, but other than that I think her voice is great.