D.D. I have always believed that there were synergies in using the same product in a system, but anymore, I'm not sure what to believe. I think I am becoming a skeptic in my old age. The quest to find the perfect blend of copper, silver, and snake oil, can be a challenging one. 
Rick
There appear to be two going theories on using consistent loom (brand / models) in your system:
1) Loom (cables) are designed by the engineer by model as a family to complement eachother with the objective of an overall neutral or specific sound in mind. The engineer designs the loom to work togther from source to speaker. Hence, if you like the sound of the loom, using it across your system will give the best results in terms of you getting to the objective of the engineer.
2) No cable is 100% neutral and neither is any component. No cable / component is 100% the same in characteristic sound. Therefore, using the same loom throughout may result in defficiencies in the cables being built on and exaggerated. This will mean too much of a bad thing or too much of a good thing - which is bad, as well. Therefore, using different cables will tend to offset the inherent defficiencies in the brands/models resulting in a better state with an overall average.
I see some sense in both theories but don't support one over the other.