Another issue with NAT in large scale deployments is the limited number of simultaneous connections possible. I believe this was best demonstrated by the screen

Another issue with NAT in large scale deployments is the limited number of simultaneous connections possible. I believe this was best demonstrated by the screenshots of how Google Maps starts degrading when you drop the connections available; 15 saw marked degradation, and that was without any other software running. Can't remember the source of this though now.