First of all, the ligature produces an amazingly clear sound. The best manifestation of this is that I find more reeds are playable, as the ligature reduces stuffiness in the tone.
I am attaching two images from from the Spektroskop sound spectrum analyzing app that I use on my iPad. One image shows the image of a throat A, with a good “resonance” fingering, played with my Vandoren leather ligature that I normally use. The next is with the Silverstein ligature.
You will note that there is a nice bump in the presence of overtones between about 3K and 8K on the Silverstein. I think this accounts for my perception of a “clearer” tone. The Vandoren leather ligature, it appears, serves to “darken” the sound of lighter reeds. When I first started played the Silverstein, my sound felt a little on the bright side in comparison. However, since I can now play more resistant reeds while retaining center and clarity of tone, I really like the results on the Silverstein! It just requires a different reed and getting used to a slightly different “feel.”