sftp://host/path/to/file points to path/to/file under the user's home directory. sftp://host//path/to/file points to an absolute path on the remote host.
add exclude_attributes to configuration to avoid copying attributes (note that there is currently no command line option for this)
can more readily be used as a library) eliminate print statements or at least make them replaceable via subclassing. make sys.exit calls replaceable via subclassing.