Well...... I no longer own the TC harmonizer. I sold it B4 Christmas, so an A/B sound byte is out of the question.
Here's my findings:
1) The TC has a superior effects section
(not so important for live work)
2) The TC had a cleaner signal
(again, more noticable in a studio setting)
3) The TC took up 2 rack spaces .... I prefer the smaller, 1 space unit. I bought the Quintet late last year but could not use a conventional footswitch to trigger the harmonies, so I returned it.

The benifits for live work were marginal, so I stuck with the Digitech. Through a PA system, the difference would be pretty minimal, but in a controlled, studio envirnment, you'll appreciate the quieter signal from the TC.