I ordered 2 SBD strings for my A&H bow off of the A&H website. The small gain in arrow speed is nice but I was mainly trying them out because Pierre claimed that the skinny strings would be quieter too.
I must admit that I really didn't believe it. I'd always heard a "heavy" string was quieter. However, to my ear, the SBD strings were noticably quieter. Some will argue that they really aren't just the "tone" changed. I didn't measure the sound difference on a meter but there was a significant difference to my ear. This reason alone is reason to try one.
Note, the serving on the ones from the A&H site is too small for my Gold Tip Hunter nocks. I wrap the serving with floss and it works for quite a while before it wears through. A bit of a pain though. So make sure you get the diameter serving that fits your nocks.