I don't think anyone is questioning whether the change is worth it or not. It's free and a simple fix, but I don't get the "not wasting my precious time doing comparisons" logic. If that's the case, just ask Bruno which speakers, source and preamp you should own and be done with it. Isn't half the fun of this hobby the discovery of what sounds best to you?
I enjoy doing comparisons, amps, cables, speakers, etc. It's part of the journey that helps me identify what sounds best to me. If I like the sound of old cables better, I'll put them back in and be happy with my decision. Bruno is a very smart guy and I expect the new cables to sound better, but I fully intend to "waste my precious time" comparing one channel to the other and making an objective evaluation. Since my Ncore amp sounds pretty darn good, I'm not expecting the new wires to sound dramatically different. There is only one way to find out!
Cheers,
Jack