(First post, hi everyone).
Ok I just did my own cable test two weeks ago: 20ft Whirlwind / 10ft Planet Waves Instrument Pro / 5ft Mogami / 10ft "Horizon" brand. Sorry no audio files to post, but results were similar to the ones on this thread.
Conclusion: it's all about the cable capacitance. The Planet Waves and Mogami had the lowest, while the 20ft Whirlwind sounded identical to the 10ft Horizon.
Did some research and turns out the capacitance
doesn't just bleed off the highs, but also
shifts the resonance peak of the pickup/cable (inductor/capacitor) system. It's an LC tuned resonant circuit system. The peak is usually anywhere between 2k and 5k. Higher capacitance shifts the peak toward the 2k, good cables toward 5k.
Using a good cable therefore releases the highs
and shifts the ringing/resonance higher. That's why a higher cap cable (lower frequency resonance) creates a half-cocked wah pedal sound, which is why Hendrix and 70s purists prefer long coiled cables for maximum capacitance.
Long story short, I was annoyed at the Mogami and Planet Waves cable because while they made my guitar clearer like in example (A), it also had an ear-piercing resonance in the 4.2k region. Through distortion, my tone became thinner with less perceived dynamics. My guitar's bright anyway (Horizon NT II with Crunch Lab in the bridge). So I ended up soldering in a 330pF capacitor in the guitar, parallel to my pickups, and now I've got the higher cap tone (more dynamics and body) plus the better reliability and lower noise of the Mogami / Planet Waves cables.
Also, changing cables is different from using the tone control on the guitar. The first changes the resonance peak position, the latter merely changes its height with the position set by the tone capacitor. The Varitone tone system uses a rotary switch to switch between several capacitors instead of a pot to vary how much a single cap affects the sound.
Here's an article that explains it all with diagrams:
http://buildyourguitar.com/resources/lemme/