So far I've heard that it's fun, but there are no faction like in New Vegas, Karma is totally gone now, skill system feel more like Skyrim, no traits, no hardcore mode, raiders are called "raiders" again- in one terminal someone even writes he wants to become "the best raider ever", quests for building your own towns are always repeating (kill stuff), etc.
It's kinda fun, but everything that goes into the direction of story, quests, skills, and atmosphere, was simply better in New Vegas.