For me the injector blade has always been superior to any DE blade in terms of effectiveness and longevity. I think it was
@chazt who first mentioned there were RBSR's which allowed the use of an injector blade. For this reason, I was immediately curious.
He had ordered one such holder that unfortunately and no fault of his own did not pan out. The Cool Cut 9 did work out for me to be a holder which would allow me to use an injector blade even though conventional blade holes do not provide a snug fit and the Personna Mini Blades must be employed. In fact, the history of his holder may have connections to Personna. Seems like I remember reading something to that effect.