Yeah definitely crashing a lot. I've got a 33% round completion rate or something. But so worth it.
Pretty much everything I didn't like about BF3 has been fixed. VoIP with people not on your friendslist. Voice commands showing up as text in the chat so people know who's talking. Leaning. Recon has C4. 5 man squads. Knife takedowns can be countered from the front, but not from the back, discouraging people from using the knife unless they know they're unseen. Commanders. Vehicles don't have unlimited ammo.
Plus, the obliteration gamemode is the best addition to the franchise since conquest. The center of the action moves all over the map.
A big thing that still annoys me to no end is how vehicles can still unlock infrared view, and reveal nearby enemies on their minimap. Like they aren't powerful enough against infantry, you also can't hide from them.