I thought the combination worked well. And Wolf, if you haven't seen them with the first singer, you may like her as much as the third.
From what I read, most of what they record includes symphony orchestras. I watched a few of their live videos, and while I'm not sure, it did seem to me that there may have been more musical content than was being produced by the musicians. Put another way, it seemed to me that perhaps the orchestral and choral parts were not being reproduced by a keyboard, but by a recording.
Which is a whole, and perhaps interesting, discussion in itself.