Here are my impressions of Battlefield 4 after approximately 15 hours played in both the beta and the actual release.
Battlefield 4 is not really a true sequel to Battlefield 3, the game is largely identical to its predecessor with improvements and gameplay tweaks making it more of a Battlefield 3.5 than 4. This is good in the sense that it retains and refines Battlefield 3's excellent gameplay, and bad in the way that the game is not really revolutionary or much different from the 2011 release.
The gameplay is a lot smoother than it was in Battlefield 3, especially in infantry combat which makes it a lot more enjoyable. I hate to say it, but it actually feels a bit Call of Dutyesque, nevertheless it's for the better as the game retains it's open world and vehicle combat which has made the series so popular.
The multiplayer is, and almost always has been in the Battlefield series, the main selling point of the game and it remains fun, frantic, and an absolute blast. You can choose anything between 2 to 64 player servers in brand new maps which have some very cool destruction which really brings the game alive. Unfortunately, though I have only played a little bit of it, the single player remains somewhat lackluster. I expected DICE to improve their campaign after what was a rather mediocre experience in Battlefield 3, but it seems that once again it is somewhat of an afterthought.
There are some kinks to be ironed out, the sound seems to go in and out at random times, there have been complaints of texture popup, the jets seem to need re-balancing, and I am still not a big fan of having to use a browser based server list (but I doubt this last complaint will ever be changed). Based on DICE's track record I have faith that they will eventually fix most of the problems and the game will continue to progress. Keep in mind that you require Origin, the Battelog browser plugins, and Punkbuster to play this game, these are all things that were required in Battlefield 3.
IN CONCLUSION: Battlefield 4's single player is okay but not great, it might not be the revolutionary sequel some people were hoping for, but it is an excellent multiplayer game that will keep you hooked for a long time. In that regard, Battlefield maintains the Status Quo.
Definitely recommended for fans of multiplayer FPS.