Bill,
The voices are pretty good, but nothing that would excite me. I, personally, would not be using the gospel voices, the rap voices were hokey-sounding at best, but the one I liked best was the Choir Accapella, which really sounds good on a high-quality sound system. And, at the prices stated,12 to 16EUR seems a bit steep for each voice.
As for being better than Yamaha, Christian, IMO they're not nearly as good or as versatile, but that's just my point of view.
Thanks for the links, Bill,
Gary