I don't know that I necessarily feel I 'need' to change anything. I have also invested a lot in my equipment, but have not really thought about my cables that much. There is a part of it that feels kind of technical and the more logical side of me says that I want some consistency (aka synergy) in my system to let the strengths come through.
I also don't know that I feel like it is immediate. With some things, I like to do fast upgrades. If I decide that the cabling is important, it is probably something I would change over time--especially since I would likely make a decent investment in the cables.
I hope that makes sense, and I certainly know what you mean about letting sleeping dogs lie--just not one of my strong suits.