XS116 is silica braided tubing, XC116 is ceramic braided tubing. I haven't tried the ceramic yet (due to ordering the wrong stuff from the same place you did.... doh) so I can't tell you about the difference in flavor/hit etc but I can tell you the XS116 works pretty well. I was able to heat mine up with a torch to the point it glowed orange and it didn't burn away or give me a burnt taste.
Right now I've got a small bit of it over the top of some 1/16" OD 7x7 316 stainless rope with a kanthal ribbon coil and it's hitting great. Clouds of vapor and a good flavor coming
through. Eventually I will try the ceramic but for now, this is
vaping to well for me to mess with.