I have had it with powder coating. In theory it's a great surface coating. In practice I have found that the slightest imperfection in the coating allows for moisture migration which then leads to de-lamination of the coating. There are far better coatings available if your chief concern is anti-corrosion of the base material. And unlike powder coating, they can be touched up easily if needed.
Bottom line, powder coating has it's place in the automotive finish world, but it's not always the bullet proof coating that many think it is.