Hi Uncle Dave,
I am rather envious. I bid for the voice prism on ebay a little while ago but was scuppered at the last minute. (That will teach me not to be so cheap with my maximum bids ) WOuld love to hear your thoughts on it when you have had a chance to put it through it's paces. Have you seen the presentations on the T C Helicon website? From what I could gather the addon card seemed very expensive for what it purported to do.
One of the mags over here in the UK did an indepth review of the Voice prism plus. I think I still have it somewhere so if you are interested I will root it out and scan it for you? Just let me know. From what I remember they loved the voice prism, saying it was the best vocal harmony product on the market. However they said that the difference in price between that and the plus was not justified as the technology was not quite ready to meet expectation!
ttfn
Tony