so should I save my old blades and take them to a jeweler to turn them into a necklace? jk. there are different types of thin coating they put on the blades supposedly (iridium, platinum, Teflon, ceramic, etc.) IMO if you like how the blade performs then then use them. by sticking with one category you are limiting yourself and could be missing out on something great. same thing goes for people that will only use tallow soaps when their are so many great artisans that non-tallow based. Basically there will be good and bad for any category.
Any coating is use to increase the smoothness and longevity of the blade edge. Some people also have skin reactions to chromium, nickel, platinum classes (platinum / rhodium) so having a choice of coatings also allows for choice in use. For more look at this thread and the links therein. http://theshaveden.com/forums/threa...ild-sharp-or-smooth-a-general-overview.37813/
I had one tuck of Feathers laying visible. My wife happens to see it and reads "Platinum" on them. She got upset thinking I have been wasting money on blades made out platinum. I had to explain that if they at all have platinum, it is a very thin coating on the edge. I do not remember if Feather actually have platinum or not. Many blade brands use the word platinum to describe the quality.