I really didn't enjoy the final part of this anime, especially in regards to the fact I read the manga first. Just a spoiler alert for anyone reading this in case you haven't finished or even started it....
Firstly, in comparison to the manga, several arcs were skipped, some of which were really good ones. I was really looking forward to the Chess Club arc, and the Astronomy Club should definitely have been done considering the godess was in this season. There was a massive cut in the story, and it definitely ruined part of the whole flow of things for me.
But I think the worst part was the ending. What the hell happened to it? In the manga, it was obvious what happened, and there definitely wasn't any of this "feel sorry for the main protagonist" crap. I was really hoping it was going to have a good closure, and up to the very end it followed the manga's ending perfectly. But then it just cuts off with him walking out the door, what the hell is that?
Overall, this season ruined the whole series for me, and I really enjoyed the manga of "The World God Only Knows". I will definitely be telling anyone to avoid watching this anime because of the sear disappointment of this one season alone.