Well, I'm no expert, since I've never used ceramic myself, but I've heard they are terribly fragile. I think accidental breakage is probably the deciding factor in how long they last. I've read many people in the Rebuildable section here have used them for months without needing to replace.
The experience I have with the SS version is really good; I find them very easy to set up after reading eHuman's blog on genesis atomizers. If I can rebuild a gennie (I have AGA-Ts and RSSTs as well as the ZAP), then anyone can.