“Honestly I don’t know how Serpa continues to sell that product.”
Maybe it’s because they work and work well. When properly used they index your finger right where it needs to be, along the slide. It’s called “muscle memory”.
Maybe you’ve heard of it.
L
Too often they memory muscle train the user to press the release before pulling the gun from the holster and transitioning to finger on trigger with said press before the gun is rotated to the target or safe direction.