Having been a part of a few different chamber choirs and having sung Eric Whitacre's music a few times before, this is really really really cool.
Besides all the really cool advantages to a virtual choir, there are only a few downsides that I can see. One is that you can't really rehearse which makes a big difference for just about everyone's performance. The other is that you don't get to hear the rest of the choir while you sing which is a joy for me personally. I guess the trade off is that you get to hear the final product where as you don't when you sing as a group unless a high quality recording is done.
Either way, this is pretty cool to hear.
