Well, I think the easiest comparison to make is against Man of Steel, which I am not particularly fond of: I think it's an incredibly strong film weighed down by its third act. So I enjoyed BVS immensely, and consider it an improvement on MOS, while simultaneously advancing it's story and it's characterization of superman. I think there are certainly weak points. I am bothered by Bruce firing at anyone, whether they survived or not.
I think Lex is a mixed bag, Jessie plays him very unstable, almost like a person with a savant syndrome or at least a severe social disorder; it's fascinating, to be sure, but not necessarily the Lex I grew up with. I don't appreciate Lex willingly sacrificing Mercy, as he comes across completely unhinged, I dunno, I just consider Lex to be very calculated and careful. But it's excusable.
The core conflict between Batman and Superman never seems real, to me. It's certainly pushed by lex, and they both believe in the conflict, but as a viewer who knows they will make peace, I'll admit that it was hard to invest in. That said, the final moments of the fight, as Bruce's foot is in Clark's face and he's holding the spear above him ready to kill THAT was one of the most intesne moments I've experienced in a comic book film. And the weight of superman's sacrifice was honestly heart-wrenching. The open casket funeral at the Kent farm, and Martha's talk with Lois absolutely destroyed me.
It's hard to evaluate my feelings, the next day, but if The Dark Knight and Batman Begins are both 10/10, then this is a solid 8, maybe 9 for me. I really did love it.