Frankly speaking this war arc is 'good written arc' from Naruto, but it pales when compared to war arcs from few other mangas, with which Naruto is compared usually.
Where it fails, here is a list of points from my side.
1. Very few known characters died: When it is war, people expect sacrifices and death of secondary or major secondary characters, and that's where this war arc failed. The only character which died during this war is Neji, and Kishi missed 'giving nice ending' to two main characters, Gai and Tsunade.
2. Few panels were just unnecessary: Common example being the panel where everyone pushes them bijuus out. It was completely unnecessary, rather Kishi would have reduced the length of many chapters if he would have taken out few panels and avoided repetitions.
3. Inconsistency in roles of characters: Many characters wasn't able to deliver when it is expected that they should at least give a try or were completely off-panel for number of chapters. Common example being Killer Bee going off panel for number of chapters.
And many other reasons, currently leaving these few points.U_U