Better is subjective. It can definitely help "the human operator" to use one port as it reduces configuration problems where the human uses the wrong port. It's perhaps slightly better to have fewer ports from a firewall perspective too I suppose?
Neither of those are particularly compelling to me. What IS compelling to me in favor of one port is that it allows using the two most common ports: 80, 443. Lots of corporations will block many/all outbound ports, but often leave 80/443 open because "that's the internet". So, if you want to install a router and a controller on ONE node, you'll have two options:
- install a TCP-level proxy and use SNI (this allows you to use one and only one port)
- install a controller/router using SNI and leverage ports 80/443. (generally port 443 for the controller since that is the HTTPS endpoint)