Should Iron Reflexes be avoided?

My Ranger is lv 36 now, in Act 3 Normal, and all my deaths are due to not knowing the enemy pattern prior to facing them (or I'd anticipate them).

Piety in Crematorium left me not knowing what to do really until 3-4 deaths, then I just hit-and-run her by moving door to door, until she left.

I have 40% evasion only as of now, but I upped my HP significantly (from 320 at lv 30 to 650 at lv 36) using HP nodes and chance gear (rare rings with +life). I really did notice the importance of going to all +life nodes right off, and finish the build with the damage ones.

I'm only taking the "paying" life nodes though, Fitness +10% and +str, +12%, +18% (and the 8% in their way only), as my build is a physical ranger attack speed build, and I think +116% is going to be sufficient.

Before I even try out HC, I'll bring my (full-evasion very high DEX, Acrobatics) Ranger to Merciless Act 3, and gauge how well it does then. Then I'll try to bring my IR (a bit more balanced stat, DEX still highest) dual claw Shadow over there too. And then I can compare their survivability (they take the exact same HP nodes).

Iron reflexes can help make up low HP for generic hits, but you still get slammed for crits

Having high HP + high evasion is better though all around