Frankly, I don't know what the difference is. But of the fabric that I got recently from Spandex World, I'm pretty sure it was one of those that I liked the most.
I have of course switched tactics. I now order swatches from the companies I find, and I ask that they label the swatches. I found another place today.
I put in a request for swatches of the following fabrics:
Really hard to predict what will come back, but I'm very curious.