You are opening a topic that has been the subject of considerable debate here...polishing!
I don't have any knowledge of anyone's experience with Gords. They were on the forums here some months ago promoting it, but I never read follow-up.
From looking at their website, it looks like it's a chemical based polisher. Typically this involves using acids to etch away a layer of patina (the dull surface). The trouble is, the aluminum on our trailers has a thin layer of more reflective metal (aka, alclad). Folks get concerned that the chemical polishers are too aggressive and eat this layer away. It appears that the only reliable measure of a polish's safety is whether it meets Boeing's certification standard for use on polishing its aircraft (which are also alclad)
From my reading, the most trusted polishers for airstreams are two products, Rolite and Nuvite. These use particles to cut away microscopic layers of patina from your trailer, while still leaving the alclad in place. There's a very involved process to using these--but one thing folks seem to agree on is that (after much buffing) they can safely achieve a mirror shine.