I'd say the gameplay, especially the shooting mechanics, are a huge improvement over previous Fallout games. The protagonist is now fully voiced, which is a nice touch. I also like the new crafting and power armour mechanics as well, more in depth and overall more interesting to use. The story is also decent, not as good as NV, but better that Fallout 3.
Whare is game's weakness? Basically, in the overall RPG experience itself. It's not easy to get the best out of the leveling system and both the dialogue and branching choices feel more limited than in previous games with some dialogue options not changing anything. The settlement feature was also nice idea, but to be honest it wasn't well executed, and I can only imagine that it's even worse on console. It's frustrating, pestering and difficult to use.
It's a mixed bag, but if you're willing to up with a slightly more inferior RPG experience in exchange for better action gameplay, you should enjoy it.