waywardsonI'm sure part of it is the "tacticool" marketing angle to selling knives branded by a gun company, but there's a practical purpose as well. D2 steel is only somewhat stain-resistant, not stainless, so the coating serves as a protective barrier so that you don't have to be quite as careful to avoid spotting, etc. I've never had a problem with uncoated D2, but other things equal would rather have them coated so that I don't have to think about it.
waywardsonAre the HK Axis or mini-Axis available with a non-black blade? I don't recall ever seeing that variant - could be nice. It seems like most of the HK catalog is only available with a black blade.