Heros were a nice addition.
The campaigns themselves were hohum.
New classes are pretty decent. For pve, Assassin underpowered, Derv overpowered. Dont have much experience with the others.
Nightfall was the worst one, the campaign was literally the most blatant excuse to waste your time with go here fetch this crap quests and it just went on and on. And if you moved your character over... guess what, you get to do the quests from the beginning with a level 20 character. Nothing says fun like spending hours running through level 4 mobs so you can reach the content that is actually geared towards your level.