Not only does flawless heavy armor make you virtually unkillable with consumables (aloe pot outheals full greatsword combo easily), but the stat bonus is a +9 vs. a +8 when compared to lighter tiers of armor.
@Funcom if you want to make lighter armor viable you will need to change all flawless sets to add up to +9. Currently there is really no reason to wear it if your goal is “not dying” and maximizing your build.
That is all.