I was very happy with it, and glad for the length. I don't want to spoil anything but want to make a few safe observations.
First, WOW on Affleck as Bruce Wayne/Batman. Total superhero redemption here, and finally the Batman on screen we've been waiting for.
Second, there are some nice nods to Frank Miller's TDKR other than the BvS fight. If you've read it, you'll recognize a few things.
Third, very nice turning point to bring Batman and Superman together as allies - it's something that I've strangely never considered before, though it should seem so obvious.
Finally, it's not as predictable or shallow as I was fearing. It's IMO DEFINITELY better than MoS. I have a feeling most fans will love it.