I wish Digitech would hook up with Yamaha and incorporate their VH technology into future Yamaha keyboards.......TC Helicon is very good but I always had a affection for the warmth of the Digitech sound for example on the VR units when using VH in my live act and studio recordings over TC....another alternative when recording in studio is to do it track by track without a VH at all as I have done many times to get the exact harmonies I need especially with passing tones in a song.......

KORG 80 I would get the PA900 or Pa3x either way is a better choice over the Pa600 IMO. Good Luck