On level 70, i.e., RoS, life steal will return 0% damage to life - which means it's gone.
Life steal in 2.0.1 is still a pretty viable way to survive. Rather than boosting damage to compensate for the smaller return, I'd recommend to up mitigation (armor and allres) - it'll make the transition to level 70 much smoother. If you keep a glass canon style (500k DPS and 500k EHP) you'll not only hit a brick wall at level 70, but you'll even get into trouble when leveling up (the later act 5 parts really require more EHP if you want to level your char on Master or higher in RoS).
100% Normal, 70% Nightmare, 40% Hell, 20% Inferno.
Since 2.0.1, life steal went down to 10%.
On level 70, i.e., RoS, life steal will return 0% damage to life - which means it's gone.
Life steal in 2.0.1 is still a pretty viable way to survive. Rather than boosting damage to compensate for the smaller return, I'd recommend to up mitigation (armor and allres) - it'll make the transition to level 70 much smoother. If you keep a glass canon style (500k DPS and 500k EHP) you'll not only hit a brick wall at level 70, but you'll even get into trouble when leveling up (the later act 5 parts really require more EHP if you want to level your char on Master or higher in RoS).