Wow, this was such an interesting topic I hated to see it die out so early.
I could go on to say yes, there appears to be 'some' difference in cables. I thought the info regarding the use of twisted pairs quite interesting and certainly supports a well founded theory on reducing the effects of EMI.
I still use Kimber 4TC , because so many audiophiles who assess speaker cables agree with me (haha!) but it does make a difference over lamp cord. Where they will argue to eternity over which is really a great high end cable. Interestingly, the 4TC is made up of multiple twisted pairs, and is reasonably priced.
Other differences, Bettercables for component and S-Video. I observed a better picture with Bettercables SVideo over an equivalent priced Monster cable. Enough of a difference, I did 3 swaps to make sure I was really seeing a difference. Now, it may also be related to the fact that the Bettercables had superior pin retention.
I use a IXOS combined (single jacket) for the 6 channel analog connection (DVD player to 5.1 input) for the convenience and excellent construction. For $70 I find it to be a great solution and takes away nothing from a fine audio presentation.
Lastly, I like the Outlaw cables, but would prefer a push-pull locking sleeve over a twisting sleeve, especially in tight spots.
But always liked the locking concept.
Better yet is the outer ground on an RCA connecting FIRST before the center conductor is inserted. Always better to 'ground' first in any electrical connection. There was a company producing such cables, but haven't heard about them in a while.
There is no doubt that cables can be a weak link, as they can be in any electrical or electronic system design. Look for good construction, good material (harder to assess but teflon insulation is a good start for coax) silver solder, look for clean and shiny connections, etc., you get the idea.
Burn in? Serious doubts myself, but on speakers for sure! After all they are largely mechanical devices.