Is worth getting?

My DS broke so i would have to get a new one. Since its doesnt make sense to buy a outdated system i want to get a 3ds.

Pokemon X/Y are probably going to redefine the series so id like to play BW2 before.

So is BW2 worth the purchase if you already played BW1? What are the major differences? Hows the story? BW was a little preachy for my taste