I had mine Swain Tech coated with their "White Lightning" ceramic.
It's a plasma-sprayed actual ceramic coating and it really does do a good of reducing underhood heat.
I can't speak to the Jet-Hot or other coatings. I've come to assume that they are "paint-based" which I've been told is a less-rugged product...but I haven't directly compared them. They damned sure LOOK better than the Swain Tech does, but I can't speak to their performance.
