Most of the bop dungeon sets are equal or worse than boe overland sets.
The armor sets in maelstrom seem to be for as of yet non existant ice builds.
The worst ones are the potentially awesome sets that just were made too weak, like glory or thews of harbinger.
4% hp is a tiny amount even with max hp, it's why red diamond sucks, it's why the health from leeching strikes sucks, it's why thews hits like kitten farts.
Everyone uses the same stuff because all the interesting effects are underpowered, it's just a math game to squeeze the last drop out of spell damage for dps while tanks have to use random dps sets to try and act as buff maids.
They need to overhaul the sets so that they are more viable instead of nerfing everything.