ZS blends Nolan storytelling (a "first contact" story with character arc reminiscent of Dark Knight movies - it shares an interest in the symbolic value of heroism) with a wonderful visual dynamism.
ZS adds emotional heft and internal conflict. Some of the best scenes are quiet character moments, like when Clark goes to a church and asks a priest for advice, and is advised to take a leap of faith. Clark comes off as a MULTI-dimensional character who faces real choices and consequences, not a cartoon with "funny" quips.
Fight scenes have a sense of dramatic stakes, like the good guys are having a tough time and could plausibly lose (which makes it cathartic when they win, something MCU movies NEVER have).
This is a story, not a theme park ride. GOOD.
The action is amazing, with some of the greatest fights between superpowered beings ever shot.
IMO Snyder makes the speed and intensity a little disorienting, and gives you a sense of how scary it would be to be anywhere near a fight between people who can plow through skyscrapers and tanker trucks without a bruise and melt steel beams in seconds with a hard stare.
Not even the Hulk fights in the MCU come anywhere close to conveying so much sheer power. Not close at all.
ZS is NOT "devoted" to the source material, if anything Nolan and Snyder show a remarkable willingness to take liberties with an iconic character for the sake of lifting a good story out of the nerd dross. Again - GOOD.
When Jonathan Kent tells Clark he may sometimes need to let people die rather than reveal himself because his true nature is so momentous and earthshaking, you realize this isn't any version of the story you've heard before.
It has an original creative vision to it. This is also what made Ben A. so good in BvS, he's a cynical old vigilante who uses guns and kills people and ect., which also means he's NOT a predictable cliche.
ZS and Nolan are good directors who break the mold around these overexposed characters and find ways to surprise me. The characters are not LOL machines.
I'm honestly amazed anyone could prefer the climax of Avengers, in which the heroes drop quips and goof around and show off their powers against faceless whomevers.