The description says that you'd be 75% less noticeable and your noises would be 60% more silent. I kinda want to know if the stealth perks would actually allow you to clear a whole POI without waking any zombies up, because that sounds like it could be a possibility.
Yes, and no.
With maxed stealth and light armor (+ the mod that decreases armor noise in each armor slot), you can practically hug sleepers during the day, and literally hug both sleepers and awake zombies while inside a building at night. So long as your detection reads 0, unless you're standing exactly along/where a zombie wants to path to, they won't attack you.
The problem, as you might of ascertained, is damage. Maxed sneak attack damage, maxed headshot damage, fully modded out compound bow with steel arrows will one-shot practically everything with a headshot
on default settings. However, both radiated bloated walkers and radiated cops will handily survive -- the latter of which is knocked down to wanting to explode range.
So sure, on default settings, as long as you don't run into either of those when clearing a POI, you can completely do it without waking anything up. Run into either of those, and things become very annoying to do stealthily, since the former paths like a headless chicken after being sneak attacked, and the latter is an imminent threat which regens health too fast to reliably take down with a bow.
On higher settings? You might as well forget about it, I would assume practically everything survives being one-shot at the highest difficulty.
