Just out of curiosity, it says "Walking and running does not affect detection"
What does that mean exactly. As it is when crouched i don't have to walk slowly, i can walk fast and usually get on top of the enemy without a problem. What exactly does this skill allow me to do? Being able to not crouch and sneak? I'm a little lost. :)
Normally, you cause more noise while you're moving than when you're standing still. Some enemies detect from sound rather than sight, so if you're wearing heavy armor especially, they might notice you just because you moved.
While running (ie not cap-lock walking or Ctrl sneaking) you cause a lot more noise, which is why most of the time you can't sneak attack people without Sneaking.
While walking (or sneaking) you cause less noise, which helps for when you want to backstab people.
The perk makes it so that you only get a base level of noise based on your equipment type rather than getting extra sound attributed to you because of your actual movement.
It's kind of like a Muffle spell that's always on.