I would never say something like that. A sequel is a sequel. Whether or not you think the change is a large enough jump is for you to decide.
I think there are a LOT of changes to BF4 to keep it interesting. The fact that you can swim underwater now is really cool. The one MP map can be flooded, and swimming under water can still get you into buildings that would be otherwise inaccessible. Every map has some event that changes it in a major way. Even though they are scripted, it still adds a lot of replayability to an already extremely replayable game.
I also dig the weather changes and the networked wave physics.
Here are a few more shots. Just to.... ya know... keep screenshots going. I'm still only on the 2nd level....