HUGE difference: the Giver criticizes Dystopia, Divergence promotes it
[Small spoilers]
Just to say, there is ONE huge difference in the two similar scenario (but let me assure, none of these film are anything good or original):
In the Giver, everybody is given a job according to their specialities, living in an assigned family, but the hero then goes onto criticizing and destroying this dystopia.
In Divergent there is a huge difference: everybody gets a define job he chooses, which he has to chose over family, but in the end the divergent hero doesn't destroys the Dystopia, she just prevents it from getting different or worse, so in other word she SAVES the current dystopia she lives in.