Coreda
Member
Also, I unlocked the alternate Quen shield and it's ridiculously OP. You pretty much will never die if you have decent stamina regen, which I do because most of my ability points are in the blue tree + I have that ability where every piece of medium armor gives me +5% stamina regen.
For most of the game yeah it's incredibly useful. With the higher enemies/expansions though it frequently gets one-hit and broken through, so as a method to regain vitality it was later rendered ineffective (for me at least) so I rebuilt my tree to regain HP other ways (like imbibing any potions).