There is not really much I can add to the debate on NSX vs ACI except to share my opinion on a few things.
Let’s look at the world as it is today. It is a virtual world. At least 80% of workloads in most datacenters today are virtualized. So that leaves roughly 20% of workloads as physical. How often do physical workloads move to different servers, racks, datacenters etc? Not very often right? You rack them, you cable them, you plug them in, you configure the port(s) and that is basically where it lives for the rest of it days. Any rules or policies you need for those machines get created and that’s it.