I have noticed that SOG changes their blade/tools more frequently than Leatherman or Gerber. Sometimes the changes aren't necessarily better, they are simply different. Like the file for instance; I can pick up three pocket power pliers and all three will have a different file. Round tip, flat tip, nail nick, nail groove. Different file tooth patterns. This one double cut, that one not.
Its almost like SOG got a big batch of files from one supplier, then got them from someone else the next time.

Sorry to ramble about files, but I suspect the same thing is going on with their knife blades.