This movie was the same as the rest of Bleach and its movies -- had a good plot, but didn't really have reasons to back up why all this crazy stuff was happening. *spoilers* Like, these two siblings really admired Rukia from the past when she tried to save their lives, so they went to Soul Society and erased her existence from that place so they could steal her away from the evil Soul Reapers and then they could all join together so they could form one being? *spoilers end*
It just seems to me like they're creating this plotline out of nothing, which they probably are.
However, as can be expected of Bleach, the fight scenes are wonderful. Many characters get their chance to shine in this movie in fight scenes. If there's one thing to watch Bleach for, it's the fights.
Overall: this movie is very similar to the anime - random, out-of-the-blue plotline, which is not always a bad thing, but fantastic fight scenes.