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

Makes zero difference.

Had a set under my cables for a couple of weeks now. It's made a huge difference. 

I spend time trying to stand them all back up every time I do anything around the system.

Right now I've found them most stable stack up on a shelf

What??

I think that rather than wondering if it makes a sonic difference, we should all be doing it to keep dust bunnies away from our expensive cables. Before I used the homemade ones that I now use I would have dust collecting all over them.

i still have my 4 bose 901 series 2 from the 4 chanell days. i have a small living room so i have all 4 hanging from the ceiling! compared to when i had them on stands and now hanging from the ceiling, i can't hear no difference!