It's hard to tell without seeing a silver print of the same, but from what I can tell I made the following observations:
1. Texture control - since you are free to coat the emulsion on any paper you deem appropriate, you have a certain level of control of texture.
2. Highlights just glow with beautiful separations.
I have seen other platinum prints while visiting fellow photographers and museums, and there's a certain 'depth' to them that's hard to explain. I find them 3-dimensional and dynamic.
Hope that helps.