Back on topic, DX3 uses regenerating health which is the epitome of easy. It's lazy on behalf of the designers (they don't have to worry about health pack placement or what kind of finite health system they'd use) and on behalf of players (just hide behind cover for a few seconds to completely heal yourself).
Assuming you can find cover.
Is it really that different than Deus Ex? In Deus Ex your life was merely determined by how quickly you could pause the game. If you took a beating just quickly pause, use five medikits, then unpause. And, with the only useful aug being health-regen, you were almost guaranteed to have 20 medkits on you at any given time on any difficulty level.
Honestly, combat was very unthrilling in Deus Ex. Regen is certainly a step up from pausing mid-fire.