I had my system configured with Krell 400cx amp and Krell KPS-25sc with Siltech CAST cables and a Siltech powercord on the KPS. I bought a Musical Fidelity Tri-Vista SACD player. There was no doubt that the Musical Fidelity player sounded much better on Redbook (regular) CD playback. It was simply a question of older technology being surpassed by newer. It was not a subjective asessment; it was clear. So I decided to sell the KPS and buy a KCT preamp now that I did not need the CD/preamp combo. I auditioned the KCT in my system with CAST but I also auditioned a Pass X-1 preamp with Purist Audio Venustas IC cables. It was a blow away. The Pass sounded that much better than the KCT. Quieter,, more dynamic, loads more detail, wider soundstage; in every way more musical and more alive sounding. But I still have my Krell 400cx. I also have their newest DVD player.
I love Krell the company. Their service has always been so sharp. People there are smart, nice, and the turnaround is fast. But the audiophile world is so competitive and I can only tell you what my ears told me.
By the way SACD is truly the way to go and greatly superior to REdbook CD.
I encourage you to listen to the format.