Wow! Good thread. I also enjoyed everyone's views on this.
Anyways, Fluffy, to me there is. I was in TSD first. I had so much trouble with the back kick. I practiced it so much that in TKD, I just can't change it. People say I kick funny. But it's the way I was taught.
If you look at FearlessFreep's post with the pics, The first pic is how they do the back kick and spinning back kick in my current Dojang (TKD). That's how they end up. But the second pic, is how I end up with the back kick/spinning back kick (my foot looks like it's in a side kick position with the heal as the striking surfice, and toes pointing down while looking at my partner). Some say it is a spinning side kick. Neither of my dojangs used this phrase. So, to me, it is a spinning back kick.