Gnucleus does drop unresponsive hosts, but does not use flowing traffic as a way to analyze the quality of the connection.

Connected to 6 people gets you pretty much good access to the network no matter who you're connected to.

And as time goes on you settle on very stable connections that generally migrate to the core of gnutella depending on how long your connected.

There are still some very basic routing issues that gnucleus and other clients need to analyze to start making rational descisions on which connections are quality.