If it was any other setting I would say , "You shoot i'm in the head, he dead". Doesn't matter what "level" he is. Doesn't matter what kind of badass he is. If you get the drop on someone and line up the perfect shot. He dead.
In cyberpunk though... its a bit more grey. you get the drop on a Solo (somehow) and shoot him in the head (Or even just a random Booster Ganger) and he could have a Skull with Bullet resistance rivaling a concrete traffic pylon.
But for the typical guy or even the typical ganger, getting shot in the head is bad news. I've seen this exact question posted in multiple places in relation to this game and I have to assume that the question comes from people that have never played the game, especially when they say that people of a higher level should be more resilient than another dude of lower level with the exact same gear. That's not cyberpunk. Cyberpunk is lethal. Its a core part of the setting. people wear armor because they have too, including a helmet. Take 8 points of damage to a limb- limb is gone. Take 8 points to the head- dead. and in a setting with common pistols that do 2d6 or more damage on the regular and rifles that can spray a room with multiple 4d6 damage projectiles, you learn that on the mean streets of night city, you wear armor, you keep your eyes open, and you shoot first, or you die.
I really hope they keep this lethality in the Cyberpunk 2077 game, even if they likely have to tone it down a bit. A player should not be able to be dropped in the middle of a room of gangers and survive without extenuating circumstances (read: severe cover, stuns, strobes, etc...) you shouldnt even want to take on multiple enemies at once unless you are attacking from a defensible position and have the drop on them.
This lethality is what drives cyberpunks themes home. The theme that in order to survive, you have to more than human. The setting should drive you to get the best of the best gear. Die in one shot, or a volley of shots? The solution is to get armor. But you can only wear so much. How do you get more? Cybertech. How do you fight better? Cybertech. The lethality of the world forces the player to want to cyber-augment themselves, rather than it being something that the game tells you to do, or forcing you to do it ala Jensen of Deus Ex. And by having players make that choice they are actively engaging the dilemma of whether they should keep their humanity and risk their lives, or cyber-augment themselves and potentially lose themselves. That, at its core, is what cyberpunk is. A world where everything has slowly degraded into a pit of individuals part way between human and monster, where you can't be sure who is sane and who wants you for the parts you have. where in order to be safe from the psychos, you have to risk becoming one yourself.