I was looking for videos of Westminster Cathedral choir, and I found this. Westminster is my all-time favorite Catholic choir,and you should be able to see why.Compare their singing to the first version.It's not as sharp, much smoother. (But still brighter than your typical English cathedral choir.) It's very rich and full,quite strong.I really like this Marian motet, even if it is french romantic music and not the proper stuff.
That said, this is a really simple piece,as you can see by looking at the score.