So, GW now offers a Rough Coat product.

Certainly GW didn't invent this stuff and are rebranding someone else's product. Assuming this to be the case, what is that other product and how much cheaper is it than the GW-branded product?

Moving on, who has used it and how did it work out for you? Is it worth it?

Technique or usage suggestions?

Not counting Will J who had a can blow on him... <grin> Sorry dude.