I agree that BF4 doesn't look a whole lot different than BF3, I didn't expect it to either, I mean BF3 is already an incredible looking game. However with the limited time I played the BF4 beta, it certainly felt different.
It is hard to describe, but in Bad Company 2, I was pretty good, in BF3 I was/am terrible. Something about the way moving and shooting feels in the game. Now I know they are two different franchises, but BF4 felt a little more like BC2 than BF3. I consider that a great improvement, even though the beta ran terrible on my computer, I was able to hold my own and get some really satisfying kills. That is what is important to me in the end, if I am not able to kill anyone, like in BF3, than my interest fades, and frustration rises.
I don't know if anyone else had the same feeling.