What if you enjoyed the game but just got bored with the skim milk story after the first month and the first two expansions seemed way over-priced and haven't played since vanilla?
The new quest system does a much better job of stitching to story together. Honestly, the vanilla story was there and good, just a bit incoherent.
TTK does a even better job now in that system. The Taken story line is grouped in two quests and the Raid as the conclusion and is very engaging. Then there 2 or 3 B plots as well, equally as well done.
I'm really impressed with how they put it all together.