As @MsLing implies above, the stain tends to have a higher density as the wavelength of the light gets shorter. In other words: pyro stain is more dense to blue light than to green light. This means that image-wise pyro stain will block blue light more so than green light, which means that VC paper will effectively print at a higher grade in the shadows (less image and stain density in the negative) than in the highlights (more stain density) of the print.
Whether this is an advantage or a drawback depends on your preferences and your point of view. Some consider it a benefit since it results in highlight compression, which can help retaining tone in highlight areas. The penalty is that this tone doesn't come with a lot of contrast, so while a highlight may not blow out into paper white, it may render as an undifferentiated light tone. Again, it all depends on what you want to achieve in a print - and subject matter plays a role, too.
The suggestion of @Augustus Caesar that pyro developers are by definition problematic when printing VC evidently lacks nuance and I wouldn't agree with it. It all depends, as shown above.