FINALLY got to see this movie.
I thought it was overall very enjoyable, but the most uneven of the X-bunch. The first half felt like a clip show to me where the scenes were either good or bad and didn't necessarily connect well, and there were some plot gaps or holes too (just one example: Storm and Apocalypse suddenly shifting from Cairo to the not-so-public mutant hub in Berlin).
Apocalypse was shown to be WAY too powerful, being able to kill a bunch of people with the blink of an eye. That power would have made him impossible to fight against, it didn't really gel with how they actually could fight him in the end.
I didn't like how they did the horsemen & what function they had in the movie, especially Archangel only seemed to be done in respect to the guy being a famous horseman in the comics, but there was no reason for Apocalypse to select him in the movie and Archangel hardly did anything. Psylocke's story-arc went nowhere.
My biggest issue was how light they made of mass-destruction, death and danger:
-Quicksilver had another cool, funny scene like in DOFP, but seeing how many students were in serious danger I thought they went too far with him being silly around the various saves, taking more time than he could have known that he had with the explosion blowing all through the mansion. On the other hand, he DID save all but one student and nobody ever thanked him for it! Shortly after, in the plane, he told the others that he considered himself to be a loser. Couldn't anyone have pointed out that he had just saved a huge amount of lives?
-Jean unleashed Logan on the Weapon X facility and the guy goes on a gruesome killing spree. The only serious reaction this gets from anyone is Nightcrawler's shock and prayer. But shouldn't Jean be horrified by the consequences of her action? Shouldn't Wolverine, after Jean cleared his mind, have looked at the blood on his claws in horror?
-Magneto's enhanced power results in mass-destruction all over the world. Thousands of lives are lost. Thousands! But in the end... they won! Disaster averted! All's well again! The world leaders are reassured and Erik and Charles have a friendly chat back at the mansion. Nobody makes an issue out of the fact that at that point, Magneto is a mass-murderer.
BUT for all of the above, for all of its flaws, for all of the gaps and holes - I did enjoy the movie and I LOVED the final fight against Apocalypse. Superhero/Action movies often just 'play out' in the end, just revolving to their logical conclusion, but I thought this fight was extremely exciting. Xavier's "You'll never win, because you are alone, and I am not!" was perfect.