I had TTi coat my set. They looked great right out of the box (and actually still look good today) but on engine break-in I did not adjust the timing soon enough and the heat (it seems) was too much for one header (which blushed the silver coating on a tube or two).
There is a break-in for the header coatings too, so breaking in a cam (AND headers) may have been asking too much for my set. But... They have hung tough since, seem cooler under-hood & have not changed visually (since the blushing) a bit.
So, I say worth it.