Apart from the slight weight disparity, what does a carbon shell Fizik Arione have over the nylon-shelled version?

I ask b/cos I am in the market for a new saddle, have the nylon shell now and wondering if I should shell more money for the carbon-shelled version. I do not care about the weight difference, but if one gets more comfort out of the carbon versions, then I'll pony up for one.

Comments are especially appreciated from people who have used both versions.

As always, thanks for your insights.