Migration question and binary question

[Jerry]

I just upgraded my OS to 10.9 from 10.8 and am following the instructions for migrating MacPorts at https://trac.macports.org/wiki/Migration.

I am considering using the "Automatically reinstall ports" suggestion whereby a script is downloaded which script then works with a previously saved myports.txt. If I do this, will the script install old versions of ports which had not been active? I'm thinking that this might be a good time to do some decrufting and I would like to consider these old inactive versions as mostly cruft and not reinstall them.

Also, I've been confused about binary versions--are there binary versions of some ports and if so I would like to install them preferentially over building from source. How do I discover the presence of a binary port and how do I install it?

Thanks as always,
Jerry