Masterpiece. Rather than glorify it, Garland shows the absurdity and horrors of war without holding back. Civil War gives you no answers, but they are there if you are aware and tuned in. What the movie is most concerned with, however, is how it makes you feel. The top-notch sound and cinematography focused on realism really gives the film the visceral impact its message deserves, and that's why I recommend seeing it in IMAX if possible. The sparse moments of beauty alone are worth your time. As for the characters, I will say they served their purposes well and every role was superbly acted. I felt each death on-screen and off because every person in Civil War is human, and therein lies the tragedy.
To the critics, if you did not like this film because you were expecting a straightforward spectacle, more explanation, or something else, I only want to point out that not a single moment of this film is wasted. So if you spent more time questioning the events in Civil War than your reaction to it I guarantee you missed the point.