I have a protect a tow and it works fairly well - rocks do not pass through it - road debris stays under it and passes under the tow vehicle. It also seems to help keep the rear camera lens clear(er) when traveling in rain we have in southwest Oregon. Road oils do go through it and get on your tow vehicle. I have a diesel with a rear exhaust so I had to make a frame to help prevent the mesh from melting. It does get dirty but is easily rinsed off. I think it probably easier to store than the big hard rock shields I see on some vehicles. I suspect the Roadmaster would perform equally well.
Bob, Sandi & Marmaduke the Big Pug
SW OREGON 2004 Journey 39K, 330 Cat
If towing: a 2006 Mini Cooper or 1995 Wrangler