I've only ever owned "one" Kydex sheath...and will "NEVER" own another! Scratches the hell out of the blade, hilt, etc... I have a couple of nylon sheath, one that ,"was/used-ta-be", supplied by the Randall shop for their Divers knife.
No issues, thus far..."BUT"...(Ya' know that was coming)...a waxed sheath from the Randall/Sullivans shop fits my needs quite well.
Caveat Emptor,
Capt. Chris
PS: I even had a Kydex built, with "lining" that I was unhappy with...(I guess that means I've only ever owned "two"...)CCS