With yesterday's patch (dated 12/20/13), I thought the issue was solved. The patch fixed an SLI "flickering" problem. Suddenly I was getting a constant 60 fps on Lancang Dam, which was ALWAYS choppy (i.e., had poor framerate) in the past.
The game continued to play great for another 3 levels, then it started to get choppy again. I quit the game and started on Lancang Dam again. This time it started out fine, but got choppy within a minute or two.
So, while it seems better, they still have a lot of work to do to fix SLI in BF4. Here's hoping they make it a priority. I have yet to see them acknowledge the issue on their "issue tracker" page.
