Watched this for the first time a couple days ago. It's a solid movie but I don't quite get all the hype. Fassbender and McAvoy were good, Jackman was Jackman (which honestly is getting stale) but otherwise I didn't really care for anyone else. Usually Stewart and McKellen were the standouts other than Wolverine in the first 3 movies but I thought they were mediocre in this or maybe I'm just bored with them, I don't know. I think Jennifer Lawrence is highly overrated, I actually prefer Rebecca Romijn as Mystique to be honest. Even though she's technically not a better actress than Lawrence, she's less annoying and comes off as more sinister, which I like better for the character (though I understand that's not what they were going for here).
Never been big on the time travel theory, so that plays a part for me. I thought the Sentinels were underused, the future Sentinels were awesome though. The storyline was solid but not super interesting, just felt like the entire movie was made so they could retcon how mediocre the first 3 movies were, which just made for a mediocre happy ending scene that felt corny and contrived.
They've knocked it out of the park with the casting of Professor X and Magneto in both instances, Jackman is good but not great as Wolverine (too emotional for my tastes), Kevin Bacon was great in First Class, January Jones was very good as well, Famke Janssen is pretty good as Jean most of the time (has some ups and downs), Halle Berry is above average as Storm, Vinnie Jones was solid but underused/poorly written as Juggernaut, Romijn was good, Ben Foster is a great actor but Archangel wasn't really that interesting of a part for him, Rose Byrne was good in her support role, Svetlana Khodchenkova was very good as Viper, Ellen Page is ok, I just don't care about that character.
Outside of that group I have disliked most of the other actors. James Marsden, Sean Ashmore and Anna Paquin are terrible IMO. Most of the other actors are too young and/or mediocre actors. Still haven't seen Cyclops, Sabertooth, Juggernaut, Colossus, Psylocke, Havok, Gambit or Beast done well in any of these movies IMO, they've all been poor, mediocre or underused. None of them have been done justice.
I've pretty much given up on getting an X-Men movie that I truly love or any characters being consistently good besides Professor X, Magneto and Wolverine. Honestly if it were up to me I'd reboot the entire franchise.
I'm glad people enjoy the movies, but I just haven't really seen an X-Men movie that is truly great and what I want to see. First Class was the closest they'll probably ever come and that was mostly because of Fassbender, Bacon, McAvoy and Jones being so good in their roles. But it was missing alot of the characters I like the most.