Not good.
Between wholesale destruction of property in an age where that's just not fun or entertaining anymore (as a reminder, you're not supposed to get excited when, in The Dark Knight, the Joker blows up a hospital--it shouldn't be a spectacle when Superman flies through buildings) and some truly questionable plot decisions, this is easily the worst possible start to a less-than-stellar Cinematic Universe (you know you've got a problem when your only good movie is Shazam).
It's not ALL bad though. I could see a good movie with Henry Cavill as Superman. He has the look and the voice for it, and he's a perfectly capable actor. But it would need a better script and DESPERATELY needs a better director--Zack Snyder is hopelessly lost trying to make a movie about an objectively good person (as a reminder, Snyder is a fan of Ayn Rand and does not believe in altruism--kind of hard to write Superman in that case), and even more lost trying to give a coherent narrative. The flashbacks are infamous but honestly not that bad. They're flagged well enough that it's obvious when a flashback is starting, and they often offer insight into the character, even if he does immediately explain said insight after the flashback is over.
Is Man of Steel the worst superhero film ever? Lord no, far from it. It's not even the worst Superman movie. But it does still fail in providing the very hope Superman is meant to give the world.
Still better than BvS or Justice League tho