I've payed a few rounds so far today and it's much improved over BF3 and is the game BF3 should have been. All the menu's and spawn system are massively improved and more like a modern BFBC2 setup. The sound is also really good and the RPG's sound wicked
You will need to update to the Beta driver that was released for BF4
GeForce 331.40 Beta Driver Released | GeForce
Everyone i know running an Nvidia card found it unplayable with any previous driver, For me it was like extreme lag and dropped to what seemed like 1-2 fps often aswell as just freezing up. I lowered some settings at first which helped a bit bt not much. All the lag effect went after updating my gpu drivers but all the dust and smoke flickered.
It's looking very promising so far folk's
Edit: If you have a second monitor then you can have a live map like the spawn screen on it which is pretty cool. In Battlelog when you click to join a server and the blue banner along the bottom of your screen show's click the Battlescreen icon in the bottom right. I haven't tested the performance hit on it yet if there is any.