I have converted a few of my CZs to SAO and back to DA/SA again. Personally i do not like the feel of the flat trigger. Even if you plan on running cocked and locked i do not see any upside to the conversion. The reduced pre-travle of an SAO set up can be obtained in a DA/SA configuration by hand fitting a CGW T-3 disco. The trigger over-travel reduction is available in DA/SA by installing a trigger with an over-travle set screw.
If you are going from a stock config to SAO you do save the cost of a replacement disconnector. An SAO set up dose not require a disconector. So unless you are doing it to save money, you prefer the feel of a flat trigger or you just like the looks of an SAO set up i do not see the point.
Granted, it is easier and less time consuming to obtain some trigger dynamics by converting to SAO, but working on CZs is the fun part.