People like the "coloration" that the CX generation provided. I didn't notice the coloration (manifested as warmth over the entire frequency spectrum), until I got ZiTron cables. I actually re-purchased a CX to see how it sounded after I acclimatized myself to the ZiTron, but found that the warmth it displayed was all to obvious to my ears now.
I've had every generation of Shunyata's cables, by the way.