Header coatings, how necessary?

Wow lots of replies here thanks guys. My Duster is definitely a "driver" I use it at least once a week. I hadn't thought much about the underhood temps but that is a very good point, my current headers make it noticeably hotter under the hood than when I was running manifolds on my old 318. Not unbearable but definitely causes heat soak problems with the carb (vintage Carter AFB) and such when it's warm and sunny outside and I'm idling along in heavy traffic.

At this point guess I'll just see how much money I have to spend by next spring. I might also call that exhaust shop I got the estimate from and see what their experiences have been with header coatings locally. I live in Denver, CO btw and the humidity here is very low year-round.