Originally Posted by
Archimtiros
To be fair, Acherus fits the Death Knights very well, and while they definitely did them a disservice by not updating it more, you can't argue with the overall theme. Plus they did at least move it to the Broken Shore, which is a nice touch, making it essentially their own little Dalaran (and yet for some reason the DH's ship is still on another planet somewhere).
Also, having played through many of them, I can say the Death Knights have one of the better campaigns. It's solely rooted in "their" ideals as death knights, but still recognizes the world around them. The whole time you're raising fallen heroes they're talking about how much the rest of the world is going to hate them for it. Additionally, although disdained by many, they create a fairly compelling relationship between the Ebon Blade and Bolvar/The Lich King. This is further explored actually out in the world of Legion, as echoes of The Lich King (the first one) whisper to you. I have an theory that the (patch-extended) class hall story is going to end in a showdown between the Ebon Blade and the new Lich King, which would also be very cool if it ends up happening.
As far as atmosphere goes though, I think that Paladins, Mages, Druids, Hunters, and Rogues definitely won the lottery when it comes to class halls. The environments are very well detailed, fit the class concepts perfectly, and there's a lot of life to them, with plenty of recognizable NPCs going about daily routines. They all really feel like what class halls were meant to be.