Does raising speaker cables off the floor really make a big difference?

Makes it easier when sweeping the floor in my listening room.

Yes, at very least it keeps your cables clean, and makes it easier to clean the floor.

"...interacts with the photons traveling down the cable dielectric..." That statement alone tells you all you need to know. Sorry, but photons don't travel down the dielectric. Not in our universe, anyway.

it is depend what kind a speakers to use.   If you have cheap speakers like Bosh or any Tekton less them $1000, the raising cable dont make any difference, but if you have  expensive  especially more than  10 grand  , ---spend more couple hundred American dollars  for cable support ,and you will get HUGE  sound improvement  

I have the AudioQuest Fog lifters, and to me, they look pretty cool. They are relatively inexpensive (8 for-$149) and DO seem to tighten the image somewhat.

ozzy