Loom versus mix and match

One argument against the loom approach is that any particular deficiency in the designer's approach will be magnified. However, I'm not sure that mixing and matching can do anything to 'correct', for lack of a better word, the sonic shortcomings of any particular cable design. For example if a cable is harsh/bright, I doubt that using a warm-sounding cable from another manufacturer elsewhere in the system would have an effect preferable to the alternative of using neutral/well-balanced cables from a single designer.
 
Another thought: many people consider Nordost speaker cables to be bright, but how many people have drawn this conclusion using a full Nordost loom? Maybe the combination of Nordost speaker cables, interconnects, and power cords is needed to hear Nordost in the best light.