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

What about wi-fi?  Suspend them in the air will probably reduce jitter.  Of course there will be people saying jitter in digital don't matter.

I can definitely hear changes in cables but I have never heard a difference from raising cables off the carpet, yet I’ve always done it. I like my cables to not touch each other or the ground.  This makes my ocd happy, which in turn probably makes my rig sound better to me!

Running bi-wire cables along the top of the baseboard sure looks better. Whether it improves the sound I can't be sure. Definitely doesn't hurt, so just do it for cosmetic reasons and believe it sounds better if you're so inclined. Nobody can prove that angels and fairies aren't on your side, and meanwhile you can prove your floor is neater, so there.

Bi-wire makes a difference, that is if you system has the resolution for it.  Bi-amp will even be better.  Although not all "bi" is good.  

My hardwood floors ARE the cable risers as they keep my speaker cables from being in the basement, and since I have certified (by a panel of experts) superb hearing, I absolutely hear a difference between my current speaker cables and the ones in the basement as the ones in the basement aren't hooked up to anything...they're in a box...just sitting there. I do however want to meet the person using toilet paper rolls as speaker risers, and wonder how he got his mom to allow that...I guess she thought he looked lonely and somewhat delusional.