So, I own several CS fixeds: Cold Steel Outdoorsman, Recon Tanto, Kyoto II fixed blade. Most of them have Secure-Ex plastic sheath. And I am always concerned with that sheath dulling the blade. What is your experience, do you think the sheath is affecting the blade? Otherwise I am really careful when getting the knife from the sheath. Or should I order a kydex sheath, there are on ebay for Outdoorsman, for example.