If you are willing to try an older set of drivers, I would recommend these:
Those are the drivers that were semi-released just for BF3 at launch : 285.67's. When/if you install them, click Advanced Install, then choose the Clean Install option. You'll have to reset your nvidia control panel again after the install.
Have MSI AB open and go into a server you would typically play on: 32- or 64-man. Play for about 20 minutes then exit and take a screen shot of the open AB so we can see your gpu useage. Like this ( running these drivers):
Personally, I think the Ultra is chocking your card or cpu. I can't even run ("true") Ultra on my Gigabyte GTX 460 at 1440x900. You're at 1080p. In the end you may just be asking a bit too much of the gpu.
Try those drivers.
Try these settings:
Post AA Medium
AO Start with Off (then try SSAO, then HBAO)
You know how to do the Render.PerfOverlayVisible 1 thing in the BF3 console? Open it up and join the type of server you normally would. To start off with, watch the cpu line (the yellow one I think) if it dips heavily and you stutter, there's the problem. If your card's line dips heavily and you stutter, it's the card. Once you isolate the culprit you can work on fixing it.
Good luck. BF3 is awesome so hopefully you can get it rocking the way you want it to.