"A practical example of what I've been saying; it measures the same, but can sound different."
This is a big argument throughout audio which hampers many people for whatever predjudice they have to clearly hear differences.Sometimes differences are not as apparent until you hear a particular piece of music,then it hits you.Other times it is quite apparent.
Mea culpa, I should have made it clearer. When I said you could hear the differences, I should also have added that I have never heard any radical differences, nothing like a revelation, or the big light shining on me from the sky, and I never saw the finger of God.
Differences which could be heard, and were effectively small, but since they could be heard, and since they improved matters, differences which could not be simply discounted. They were there and could be heard.
When I hear large differences, I know that's not the components at work, it's the designer, first and foremost, and then perhaps also the components.
The argument for differences leaks over to cable differences where some think a wire is just a wire which I cannot fathom after testing a few.They may measure the same, but give different sonic results!
JMO 
I agree with that. I have heard cables in my system which all but killed the sound dead (e.g. Audioquest), and I have heard cables which allow for a smooth, relaxed sound without giving anything away to the classic values of timing, resolution, etc (e.g. van den Hul 352 Hybrid, which I am using now). That different materials will show different conduction properties is hardly any news, and logically, if it conducts differently, it will also sound different. Then there's the cable cross section, not at all unimportant, and its length (always the shorter, the better), and ultimately, purposely putting this last on the list, there's the technology of making it. I refer not to its geometry, but to the quality of the copper; for example, monocrystal technology will generally show superior results across the board, both in measurement and on audition, but it is more expensive.
These are facts which have, unfortunately, been greatly misused by, shall we say, less than scrupulous vendours to spin tales of myth and magic, attaching ridiculous price tags to their products.
I agree with Warner's posting, for $50 you can make a great power cable. I would also point out that not all are greedy; for example, a local company making line filters offers their own cable as an alternative to the usual IEC input socket for a surcharge of 30 euros ($31). While it looks, well, VERY plain on the outside, inside it's made by the book - 2.5 mm cross section conductors rolled in oiled paper, then insulated by chemically treated rubber. I asked them for two samples and exchanged some standard cabling on my gear, and was pleasantly surprised. No magic here, just some common sense thinking - quality OFC copper, lots of it, reduced skin efects, one of two best insulations all coupled with a reasonable price. I mean, $31 for 6 feet of cable is very reasonable, in my book.
Cheers,
DVV