It's more than that.
I believe the smoothness of an edge is defined by the presence or the absence of an amount of microscopical jaggedness.
Such jaggedness adds to the cutting abilities of an edge.
Within "slightly crispier" Coticule edges, I've always notices a very effortless and close shave, with some peeling effect on the skin. I have a fairly oily skin, still get the occasional pimple at the age of 40, so my skin benefits from such a mild peeling, and I kind of like the tingling sensation afterwards. The BBS-feeling.
A smoother Coticule leaves less of that micro-jaggedness at the edge (or perhaps even none), leaving a very forgiving edge to the skin. I have notices that these hones require more experience to use. Without the micro-jaggedness, the edge must totally depend on keenness to cut well, hence you can't afford to leave much behind while sharpening.
Again, do take notice that I am talking about very small differences, almost impossible to quantify well. It's all about impressions. Those who have 2 Coticules and have honed many edges on both, will know what kind of variability I am talking about. We are certainly talking about a realm, where the steel of the razor, or perhaps even the bevel angle, can make at least an equal difference.