I assume you are referring to Prime Sound Session strings ?
I have bought these for my rock/pop projects where I wanted a
smaller section sound. The sound is quite ambient, you hear a lot of "room".
It works really well and blends quite good in the mix,
but I would not recommend it for orchestral stuff as you only have 4 articulations and fast repetitions short bows are not that good ( no alternation programmed or whatsoever ).
I started programming some patches to overcome some of its limitations...
But anyway, the sound is quite rich and it does the job for me.
Hey , and it only costed me 90 Euros here, so I don't complain....