It's true that uniques make heaviest armors less attractive. What I dislike the most tho is full damage from critical hits.
There are already many ways to deal with heavy armor in the game - 2 handed weapons, high hardness weapons, passives from hammers and throwing weapons (Throwing passive is pure cheesy bullshit however), aimed attacks, armor piercing missiles, bleeding, poison, the fact that shields are made out paper and Ikea parts, and so on.
When it comes to dodgers, however, there are really only aimed hits (that actually don't work that well against them because you have crap chance to do aimed hits against dodgers) and maybe bows+high PER (work as good against heavy armor/block).
Dodgers also don't have to carry spare shields around.
So when after investing in your armor and multiple shields you realise that 25 DR isn't any better than 10 DR dodger can have when it comes to hits that actually do penetrate, you begin to question your choice of armament. Especially since you also can't do any damage during enemy turn like dodgers can.
Any unique armor is good against glancing hits, but no armor/shield are good enough against crits even by some shitty bronze arrow. And any shield can be whittled away with anything, even bronze dagger (how the fuck does that even work? My guess it's the problem of low Hardness of even heavy shields).
I'd like to see heaviest armors giving better protection against critical hits by just flat out cutting the damage. And it would be ok if that would be achieved at the expense of making them less resistant to their logical enemies - javelins and maces and such.
As for now when you play in heavy armor with block you are more afraid of RNG than actual things that are supposed to be your counters (had a pleasure of getting 20 dmg instant death crit from some shitty spear guy at Pass fight while wearing 8 Crafting blue steel Imperial Armor & Tower Shield after killing 95% of local populace).
P.S. I also have a very personal gripe against bucklers being useless for light/dodgy fighters