i don't have any first hand experience with this yet but my thoughts are similar to the 9mm 124gr vs. 147gr argument. a lot of .357 guys will probably argue that 147 defeats the purpose of the .357 round because it travels slower than the 125gr. people said the same thing when the 147gr 9mm loads first came out... its too slow and heavy, won't expand, worthless, yada yada yada.
now everyone knows how tried and true the 147gr 9mm loads are. imagine taking a bullet like that that travels around 950fps or so, and adding another 200-300 fps in .357 caliber. it may not travel as fast as the 125gr rounds, but it probably has similar if not better ballistic characteristics.
like i said, just my thoughts without having personally fired any or seen any actual testing reports on the subject.