Been a fan of Battlefield since Bad Company 2. BF 3 was disappointing when if first came out, but they eventually got the major issues ironed out. This one is no different, but I haven't experienced any major issues other than freezing every now and then.
Online is better than BF3. Bullets do great damage now, but I have a feeling they are going to nerf it in the coming months. New maps are all fun to play and the upgrades for all the vehicles and weapons are nice additions. Commander mode is fun with 24 players, but I think it will be even better with 64. There are squad upgrades that help when you stay alive with your squad and work together getting kills and objectives. The commorose is also a good new addition. At first I didn't like the new controls, but the commorose does help since a lot of people don't have a mic. As of now there is no party mode, but pushing select brings up a menu no matter where you are in the online mode. You can join or invite from the menu.
Campaign is actually better than I thought. I didn't touch BF3 and only played this one to unlock weapons online. Story was better than I thought, but its just shooting your way through missions like other FPSs.
Overall, if you played BF3 then you should expect issues at launch. You also know that it will be fixed and there is the next gen games coming out too. If you have friends and are looking to work together and shoot up some fun, this game is for you.