Regen

[Baler]

Races who have natural regen, Iksar/Troll, their health goes up while not getting hit.
Races who don't have that regen, their health does not go up.
(excluding spells/items/pots)

Spending time spot healing (not cleric healing) I notice their HP go up 1% occasionally.
Not having natural regen isn't detrimental but it helps. Especially if there is any downtime between pulls and they're not at max hp.
---
You'll most commonly find people arguing over regen vs frontal stun immune. And those debates go in length depending on the class in question. For warrior I think ogre is king but I've seen iksar do just as well.