I have never played any FO before so for me FO 4 was a totally new experience and therefor my thoughts about it are not influenced by past Fallouts. I really don’t like the character movement, aiming down the sights and the shooting itself, could be done a lot better. Weapons don’t feel different from each other no matter how different they look from each other. The ultimate difference seems to be only the damage percent each weapon does. 
But that real time dynamic lighting is what I really liked a lot. (Epic, please).