I talked to a very wise archery expert about these (all STS). He told me that there is problems in tuning the bow and increased noise (not decreased as advertised).
IMHO your very wise archery expert is not all that wise
I have the CSS on my Black Ice and one on order for my Commander.
After installing it on the BI, I replaced the string and cable with no silencers on the string or cable it is still deadly quite with no hand shock or vibe and I did gain a few fps because of no silencers.