For me, melody is king.

You've got the form and surface details, but there's no melodic idea that's holding it together. It's like listening to a guitar solos that consists of bunch of licks that are strung together - there are some pleasant moments, but it the end, it doesn't go anywhere.

Getting BiaB to create a cohesive melody with RTs is possible - see this and this for a couple my own attempts. As you've discovered, it required lots of cutting and pasting, stretching and pitch-shifting individual notes, and then looking the other way when the timbre didn't quite match up.

In the end, it's an interesting puzzle of trying to match bits up, but isn't necessarily the ideal way to go about creating a composition.

On the other hand, there are some fantastic sampled instruments available these days. And with some creative editing, it's possible to take an average MIDI instrument and get some surprisingly good results.

But that's just my opinion, and I wouldn't want any of this discourage you from experimenting!

-- David Cuny
My virtual singer development blog

Vocal control, you say. Never heard of it. Is that some kind of ProTools thing?