Switch to MacPorts SSH by default 10.8/10.9 I've installed the MacPorts high-performance variant of SSH (sudo port install openssh +hpn) but now I would like to switch the default ssh command over.  However, there appears to be some moral panic around degrading the sandbox (which was only recently introduced) but I am also worried about integration with OS X's keychain and my server keys....

What all do I need to softlink into /usr/bin/ssh or is there a better way to do this?
You can list the /opt directories before the system path and the shell will prefer the first match for ssh unless a script explicitly calls the system version.

By default, MacPorts lists /opt/ in your $PATH before the standard system paths.  I would inspect your ~/.bash_profile carefully to make sure there are no typos.