It is significantly better than what we saw originally.
Lesser minds might tell you that they were just a couple of short scenes added here and there and that they were meaningless, but these are people who didn't understand what the narrative issues were in the first place. There is a hell lot more into Lex's plan than what the original one showed. The russian agent's role is greatly expanded, the woman blaming Superman is explained, and a lot of cool references to Superman's weakness.
It flows a lot better, does a lot to get the film straight and it doesn't feel all that forced when you think about it.
Sure, we could have used another film of either character before this, but the way BvS was presented, it worked perfectly for me.
I really fail to understand what people's problem with Lex is. Can't we accept that this fiction, after all? He's clearly insane, specially after getting in touch with Steppenwolf.
Also, I don't think "Doomsday" is done. The beast we saw was hinted as a resurrected being, which means it already existed, and might come back, who knows.
What pisses many people off, including me, is why the hell didn't they show this from the beggining. The person in charge of editing the film to make it 30 minutes shorter was placed in such a hellish situation, which shouldn't have been necessary.
It doesn't even make it to the 3-hour mark (without credits).