This objective tracking game is much better done than Diablo 3, but it still lacks one thing:
There is no decent tracker to check your past completed missions.
I love the lore of these games, and I enjoy getting to know more of the environment by talking to all the inhabitants and completing their quests.
But when you have 2 missions left in a zone, you go through every inch of the map repeating zones to see if X conversation unlocked something, you’ve been crossing out the missions on various wikis since day 1 (collaborating with other players, not with official information) and not even that way it’s clear to you how many you have left… well, those desires to want to know more go away because the game DOESN’T MAKE IT EASY FOR YOU 
Please Blizzard, PLEASE! Make a list of the missions you have completed and the ones you are missing, it would be a great detail for completionists.
And... if you get bored a lot...
And if you get down to it, how about another list with all the lore in writing or audio that you find by mapping or items/equipment with its pertinent follow-up like the previous request? 
For me this game would be a 10/10 if these functions existed.