I haven\'t checked VOTA completely, but from what I understand...it\'s focus is on the really aggressive Full Choir sound.
SOV has a wide variety of Choir sounds in the one collection, including Boys Choir, Gregorian Men, and layered Pop Vocal stacked Background VOX (Enya-type sounds). The London Choir on SOV is very ambient, beautiful and smooth...with very little vibrato. It was recorded in a large Cathedral, so that ambience is a big part of the sound. There are some staccato vibrato performances too.....but I think VOTA\'s would be heavier from what I\'ve heard. SOV also has Classical Soloists with multisamples and phrases.
The two libraries are different and complement each other really well in the examples of how I\'ve heard them used together.
Hope that\'s helpful.