Wow, this is sweet! With a little better latency and less perfection, it'd be well over the uncanny valley (not that it wouldn't fool many people as-is). Are you planning to add more "human" elements like filler words or disfluencies? If anything it feels too perfect to be human. Awesome stuff!

P.S: I tried to fool the Dental Office demo trying to book on Sunday or outside of the slots it had indicated, and it did a better job than many humans would have :)