I bought my headers way back when they first came out, so maybe 10 years ago or so and the coating on them is kind of junk. The bottom especially is really flaking badly and rusting a lot, thought the tops at the flanges themselves aren't as bad.
If you're talking about the TTI headers, they have been out longer than ten years. I bought mine in either '08 or '09. I've never had a problem with mine, great fit and they still look as good as they did when I first put them in the car.