Pros:
The World and Setting -- Honestly the main selling point of the show, the set up and world is one of the most original settings I've seen and it's what kept me engaged for the most part.
Action Sequences -- In my opinion, the action sequences were well done and the art style complemented the series well.
Impact -- The series does a nice job of reeling you in (especially the first episode) and there is really nothing else like this series at the moment and the death scenes are quite gruesome
Cons:
The Characters -- People will likely try and defend them, but the characters are just boring. Eren has an enormous rage boner the whole time, Armin is made out as being really smart but doesn't actually show any indication of being that intelligent, Mikasa was cool until Levi showed up and was basically better at everything and then Mikasa proceed to become not only less useful but an even more boring character. Erwin was one of the few pretty solid characters. The rest are so dull they don't really warrant being mentioned.
The Plot -- I'll try not to spoil the plot, but in the anime and the manga the author has only shown himself to be capable of using one plot line: Eren gets kidnapped and Mikasa and/or Levi later on have to bust his ass out. The basement was presented as this cool mysterious element, but the author has not really done anything with that, and what the manga has alluded to about the titans was something I came up with 5 episodes into the show. Really disappointing in my opinion, especially when the author created a world with so many possibilities.
Mixed:
The Music -- I love Hiroyuki Sawano. I really liked his work in Guilty Crown and Blue Exorcist, but I just felt like it was kind of out of place and didn't really fit the series really well. Maybe would have preferred Yuki Kajiura for a show like this (although she tends to be a bit repetitive).
Overall:
I really enjoyed the show the first time around, but all consequent viewings caused its numerous glaring flaws to become apparent. The pacing in the show is very poor and there are many episodes where nothing really happens for better or for worse. The show takes itself really seriously and likes to act like some events were huge plot twists when it was incredibly obvious ever since the start (although there are some which are actually surprising in the manga). It's good points sadly just don't measure up to it's flaws in my opinion, which is a shame. It's worth a watch, but maybe not a second.
Side Note: I also wish there wasn't so much Eren x Levi Yaoi material around the internet
