I've used Kimber cabling in and out of my system for many years. Like anything else in your system, it's all about synergy.
This is what I have noticed as a generality about Kimber. They are a little cool sounding because of the use of Teflon dialectric. There is a slight mid/bass hump with a little leaness in the midrange. They have excellent detail and are a tad bit forward sounding. Provide good punch and dynamics. One thing about Kimber is they take an extremely long time to break in before all its characteristics jell together, especially the highs before they smooth out.
One thing that you could try with your 12TC is single cable bi-wiring, with 8 leads for the bass and 4 for the highs. When I was using 8tc I used 6 for bass and 2 for highs with better cohesion from my speakers.
Don't give up on them.