I used to have the Siltech SQ-88B and it's a great cable and pretty much worth the price, but like anything, too much of it is also not good.As in it may sound a bit on a bright side if you use all silver specially on an all solid state equipments, I never found any of the Siltech cables to roll off on the high's like Ejlif found but I agree with him on the bass which is pretty darn good for a silver based cable. I've since upgraded to the SQ-88B Gold SE which is on a different league compared to the regular SQ-88.
I would advise you to audition a Siltech cable on CD to pre and a good copper based cable on pre to amp, like the Acoustic Zen Matrix.
goodluck