I barely liked Age of Ultron, but the 75% is not the movie's score. You have to look at the average critic rating and the topc critics average. It's at 6,7. Robot action is getting stale. Ultron had bad CGI too.
BVS shocked me at first. I also liked the movie, but it was insanely flawed. It tried to be a ton of things at the same time. It was a MOS sequel, a Batman reboot, a Justice League set up, the Flash dream scene is probably a hint to a future Injustice plot, and they tried to put the most famous Superman arc ( Death and Return ) in a 20 minutes fight, lol. It was crazy, I understand its bad reviews. It was all over the place. They really need to make a focused movie.
X-Men Apocalypse surprised me, because I wasn't expecting anything. The plot was fine, acting was fine, Quicksilver scene was amazing, Magneto arc was really emotional ( better than anything in Civil War ), Apocalypse was ok. I loved X-Men Apocalypse.