The Stretch is my favorite. I have both the CF and Blue FRN in ZDP-189 and they are both great. No issues with corrosion and only a slight, spotty patina on the CF that I EDC.
The advantage of the Stretch over the Caly ZDP blades is that the Stretch blade is entirely ZDP-189 whereas the Calys are a overlay of two steels. I'm not all that fond of the resultant latter blade, but others certainly disagree.