I'm playing BF3 in bursts. Every couple of moths, I'm playing it intesively for a month or so, before it peters off again for a bit. Everytime I come back though, the game runs smoother. I was quite afraid of Armored Kill, because Operation Firestorm crashed my rig with a scary regularity at first. All the way to the boot-up screen.
DICE really is getting a handle on Frostbite 2 now. The maps of Armored Kill are insanely big, filled to the brim with details and destructibilty, featuring scores and scores of vehicles - and I've got zero performance issue on my 1GB HD5870 on high/ultra settings. It's unbelievably smooth and pretty. In fact, it's smoother than it ever was before.
How's performance for you guys? Did BF3 and Frostbite 2 improve for you too? Did the console versions get smoother too?