I have Jenifer, Laurie and Studio Sopranos. The Sopranos are really nice sounding. Jenifer is also very good, especially the way the legato phrasing links together. It all sounds very natural if you are careful. I haven't found a use yet for Laurie, but I hope to.
Strawberry was my first soloist, and I still love the sound.
The thing about 8dio libraries is that they are so purpose-built that you need lots of them to make a complete setup.
IIRC, aren't there some soloists in EastWest's Choir library?
Regards,
Dan