interesting question and it revolves heavily around security. For the sake of security and limiting the number of ports opened between VLANs I would have to choose the ACC. If I am allowed to open ports as required and this is not a security concern, and the Firewall admin has no issues then Discovery is my choice. Second security item is agent vs. agentless, some Infrastructure Admins will make a requirement one way or the other, in my experience usually agentless.
