Good news -
Changing the ICs from source to preamp within the SR line yielded a much greater sonic improvement than I expected. System got significantly more musical and organic, resolution and clarity increased, and bass got tighter, a bit deeper and seemingly faster, if that makes sense. The total presentation got considerably more balanced - the funny thing is that I didn't realize there were several imbalances until the new ics "fixed" them. My speakers have finally really "come alive". :-)
I didn't realize my Tesla Apex ics were a system choke point until I put in the new demos (Element series: Copper-Tungsten-Silver) between my CD player and preamp. Sound-stage also got wider, deeper and the imaging got even better. As a few of my audio buddies remarked, witnessing the pretty substantial improvements in so many areas - "WOW"!!
I may also try the CTS balanced from my Preamp to Amps (VAC 300.1s). I just changed this run from Precision Ref rcas to balanced, which pretty dramatically lowered my noise floor - not sure I want to change them out this quickly. In addition, a 2.5m balanced pair of CTS ics gets very, very pricey. I probably ought to first compare the cable geometries, etc.
John at the Cable Company has been a pleasure to work with as I continue my quest towards audio nirvana.