Yes, this is truly an amazing collection. I was initially hesitant to download what I suspected was not only a partial solution (being "just" sopranos) but what I thought would also be incomplete even within the context of a single voicing.
Wrong! Not only is this collection magical, versatile, and very complete in articulations and moods/timbres, but it reacts the best to MIDI-entered note-phrasing of any vocal library I've worked with thus far (most of them, except for Bela D's offerings).
Last weekend, I retracked some stuff that I had earlier used Miroslav Philharmonik for, in the pop vein, and was surprised that the results fit perfectly within the genre in spite of it being a "classical" choir. And like Miroslav, you have your choice of "warm" or "cold" voices.
I've never gotten EWQL Symphonic Choirs + Word Builder to work, and sure wish I could sell it. I have no doubt that once VSL releases a full choir library, there will be no need for Word Builder -- even if that library and auxiliary phrasing tool ever make it to the PLAY engine and Intel Macs.
The only other choir library of interest right now is Bela D's piece-by-piece approach that will refactor Diva, Giovanni, introduces The Tenor, and will flesh all of this out over time with basses/etc. The Tenor is a download instrument, quite affordable, and has some K2 phrasing script support.
The older Symphony of Voices (Akai format) will be folded into Spectrasonics Ominisphere (at least in part) when it is released next Monday. It will be interesting to get some reports on any added usability of the refactoring.