^THIS.
I personally think that overall, FT is much better than people make it out to be. The reason I'm saying this is because of Zeref alone. The way Mashima has written his character is easily the most interesting in this decade or so. Mashima has made it a point to make Zeref the focal point of the series, and he's done a very, very good job at that. I'd put it up there with Arakawa's writing of Hohenheim/"Father".
What people are supposed to be complaining is the battles, and I completely agree with them. The final arc's battles has been a complete letdown compared to Tartaros. And I have a very good hunch the Eileen fiasco was pushed by his editor, given Erza's popularity.
The background was already planned from the start, problem is he chose the wrong character for it.