Finished the WD Set dungeons since it's the only class I had every set for(well DH I had most but figured I'd just do it during season). Was pretty annoying on a bunch of them, like they're literally designed to be annoying.
Zuni for example requires you to not get into melee range of stuff, pretty easy generally, but the entire dungeon is made so you have to go "down", so you have the least visibility possible due to the isometric view of the game.
Jade is super easy in concept, but you have stupid snakes as mobs so they keep hiding and you have to wait for them to appear to kill them.
Helltooth was terrible because you need to kill 20mobs in one wall, but the packs aren't that big so you generally can only get it about in 5places(and you need to do it 4times), and you also need to clear the entire dungeon so the goals compete with each other as it's hard to group up mobs without having one that just stays behind.
Only Arachyr was really easy.