Hi, I am currently playing a sneak/dagger/assassin build. My question is about the first tier perk, "Stealth". Is it worth to perk 5/5 or should I just stop at 1/5?

It goes from:
1/5 You are 20% harder to detect when sneaking
to
5/5 You are 40% harder to detect when sneaking
could this make a substantial difference in higher levels? On paper it doesn't look so much, should I better keep those perks for the more powerful tiers? I want high level perks in sneak, archery, one handed, alchemy and light armor for this build. Thanks.

Stop at 1/5 for sure. Once you get up to around 70 nothing will ever discover you unless you're moving at running speed 2 feet in front of it in light. At lvl 100 with the "running doesn't affect sneaking" perk, nothing will ever see you period unless you directly bump into it.

Yeah, not worth it when you get the good perks.

Thank you, then 1/5 it is

...aside from standing infront of the enemy in bright daylight.

Save those 4 perk points. The perks "Silence" + "Unhindered" are all you need.

On my second assassin char I'm not even going for the highest perks in this tree, too overpowered and I prefer to save me some human error adrenaline once in a while, after all that's the reason I like to play sneaky

yeah the +5% isn't really worth it, with max sneak skill and one perk i can get dagger kills all the time