The small amount of comparative loading I have done with WSF, mostly in .38 Spl, shows that if you use Unique data weight-for-weight, WSF will give results almost identical to Unique. I have only chronographed a couple hundred rounds with the same bullets and the two powders and the WSF gave velocities slightly lower, less than 50 FPS, than the same load of Unique.
The link below should connect you to a PDF of the 2002 Winchester free manual that has data for WSF powder. There are WSF loads for the .38 super, 9mm, .40 S&W and .45 acp. Unfortunately WSF is a bit slow (burn rate similar to Herco) to be useful in the .38 spl and this manual shows no loads using it in .38 spl.