It has too many forms of currency that become useless very fast. The Reign of Madness chain is a good example of this. I still get the stuff put into my Green bag life after life, but I have no use for the ingredients anymore as I have upgraded all my stuff. We need a way to turn all forms of currency into one or the other by exchanges or put collecting them towards something else.
Edit: The random traps that are in some Gianthold quests should have been implemented in all content the day they thought of this. For some reason it only applied to a few quests in Gianthold and was never done again. This made this game fun and stopped the mindless zerging that kind of ruins the game for me. I will be in a party and the party leader gets us through 3 runs of the same quest in less than 20 minutes with around 40k xp under our belt, but no sense of real adventure.