The last 6 feet - is it important?

The question I've see many times on several forums is....

When you have 50 ft of Romex from the breaker panel to the outlet, why is the last 6ft of power cable important?

So I started looking at how some of the better performing power cables are constructed and one thing stood out - many of them had lots of individually insulated wires for each conductor.

When you construct something in that manner it normally increases the capacitance.

We know excessive capacitance is not the best thing to have in an Interconnect and in some cases in speaker cables because of the "stored energy"

But if a power cable could "store energy" then it would improve it's ability to satisfy transient demands.

So knowing Kimber cable uses multi strand conductors for their speaker cables resulting in a higher capacitance than many other brands - I decided to build a power cable out of Kimber 4PR.

The 4PR was used for the live and neutral conductors (approximately 10 gauge) and a plain old piece of multi strand copper wire was used for ground.

Each conductor had shrink sleeve added to compress the strands and add extra insulation and finished off with nylon cable sleeve. I braided the conductors to aid with RF rejection. Total cost with connectors $100 for a 5ft cable

I installed the cable on my DAC which had a Furutech FP-3TS762 20 amp 10 gauge cable with silver plated copper connectors.

It took about 5 minutes to appreciate the improvement - even before being burned in...
- vast improvement in image - deeper and wider
- much improved clarity
- much improved details
- much improved dynamics

Now I don't know for sure whether it's "Stored Energy" due to capacitance that's making the difference here. But the quality of the copper in both cables is very similar, the gauge is practically identical and the quality of the connectors are also very similar.

All I know is what I am hearing is much nicer than with the Furutech cable.

Now before you start slamming the Furutech cable - the DAC is plugged into a DIY power distribution box and the cable connecting that to the outlet is the very same Furutech 10 gauge cable.

Now I've see some manufacturer of power cables mention that they recommend a minimum of 5-6ft of cable be used for best results - increasing the length would increase the cable's capacitance, improving it's ability to store energy and provide better performance. Or is it just to get you to spend more

SO - does anyone else have an alternate theory as to why the last six feet is important?

Would like to hear an explanation :-)