What I really miss most in VIpro is an option for formant corrected pitch bend. This has been solved years ago by IK Multimedia in sample tank:
http://www.ikmultimedia.com/philharmonik/videodemo/index.php?movie=4
Though it may not sound perfect, it is a vast improvement over traditional pitch bend. As for considerations of CPU load: It could be a on/off switchable feature.
Anyone else interested?