We have been making this upgrade available to our customers. What we did find out is that not all coatings are equal. In fact many of the big names out there use poor quality coatings. The company we use has to register with the government and state to get this stuff for what ever reason.
The pics you see is on one of my bikes. Head pipe inside and out on the head pipe and the heat shields ( both sides) and mufflers where also coated. I can tell you that my primary cover is hotter than the heat shields.. You can lay your leg directly on the X and not burn your self. With the right coatings yes it makes a huge change. Cost on coatings is by the foot from most shops. Example that job with mufflers shields and head pipe is approx 275 dollars. Myself would pay 375 and never blink it works that well.
I ride in a large city , some of the nay sayers that live in the country never experience this traffic and heat. So they will have another opinion on coatings.