When I started with my rogue I had no plan. Then I was the one to become a healer and all I needed were addons like grid. Then after two years when WoW became boring I started my career as a class tester and when my damage-classes died I realized that the "limited" view of a healer does not help to keep them alive.
At that point in time I tested IceHUD ... and it really improved the survivability of my mage and hunter but it disturbed my tanks and healers. And when I realized how buggy and resource hungry this addon is I simply deleted it and installed fluidframes to move my player and target to the lower center of my screen. Did the same thing to help my dd to survive.
So my reason to not use it: It sucks