Modern installations of rsync uses ssh automatically, so if server.net is an ssh server, you can run
rsync -va username@server.net:sourcedir targetdir/
Note that skipping the trailing slash on sourcedir makes rsync create a new directory targetdir/sourcedir/.
To pretend to synchronize, use --dry-run:
rsync --dry-run -va username@server.net:sourcedir targetdir/
rsync --partial --progress
or the shorthand:
rsync -P