I've never played Cyberpunk. Closest I've played is Shadowrun (which I love).
I have had several characters that I've brought down to the limits of my humanity. Of course, there were also perks to losing your humanity in Shadowrun, which they track through Essence. One of which being that magic (as Shadowrun is a mix of cyberpunk and magic) is keyed into Essence. So getting cybered destroyed your magical skill, but it also made you very resistant to magic cast by others, so that fireball that toasted your all natural friend barely leaves a mark on you. :p