What do you think about atomic bomb?

I heard some people who think it was a good thing, that it ended a war earlier, and that Japanese killed way more than they themselves died due to the bomb anyways.

So, was it a good thing that the bombs were dropped? I think it was unfair. Sure, Japanese were not nice people, but obliterating a country with the most devastating weapon we ever knew? Why not just return the same measure, or simply battling smarter?

On a side note, if anyone ever reconsiders using the bomb again, would you agree with it?