PHP - 187 182 163 bytes
<?php $s=$_GET["s"];$m="array_map";echo join($m("chr",$m("bindec",$m(function($v){return strtr($v,[1,0]);},$m("strrev",$m("decbin",$m("ord",str_split($s))))))));?>
Pass the value as GET["s"].
array_map returns an array with all the elements of the second parameter (an array) after applying the callback function (first parameter) to all of them.
Not sure if I should take the 15% off, since echo doesn't output unprintable characters, but I didn't remove them.
Just glad I finished, since this is the first challenge I take part.